High Temperature Superconductor and Me: A Scientist's Journey Across Oceans

By Ruling Meng

Ruling Meng, the author, is an exceptional scientist from Texas Center for Superconductivity at University of Houston. This autobiography describes her colorful life in detail, with high-temperature superconductivity research as the through line from beginning to end. The book is divided in two parts. The first illustrates the fierce com

• Language: English
• Publisher: EHGBooks
• Release date: Jun 1, 2023
• ISBN: 9781647842499

Ruling Meng

蒙如玲，1958年毕业于中南矿冶学院（现中南工大），在中国科学院矿冶研究所和物理研究所从事材料研发工作。1979年受朱经武教授邀请，到美国休斯敦大学进行超导材料研究，是1986年发现钇钡铜氧高温超导体的主要贡献者之一，2000年被美国科学信息研究所从50万名科学论文作者中,评选为科研论文引用率最高的1000名科学家之一。

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Acknowledgement

I am most indebted to my dear friend, Jianjun Zeng, who encouraged me to embark on the adventure of writing a book in Chinese and then in English. She always had time to talk through a point, an idea, or the form and content. Without her numerous hours of editing, this book would not be possible.

I am also indebted to my dear friend, Zihong Zhang, who as a copy editor did many iterations of the content and form to make them fit for publication.  This book would not be possible without his tremendous contributions.

My thanks also go to Professor David Ross for his meticulous proof reading of the English texts and to Mr. William Nisbett and Professor Wei Li for their translations.

My family has been part of the journey from the beginning.  My dedication to research coincided with the formative years of my son and my daughter.  I regret that I did not spend enough time with them when I was working long hours at the lab. My life story would be different without their understanding and support.

Ruling Meng

Editorial Note

It was the fall of 1993 when I first met Ms. Meng, Ruling at the annual meeting of the Chinese Association of Professionals in Science and Technology (CAPST) in Houston. As the then President of CAPST, she was delivering a report to the members on the work of the previous year. From 2000 to 2001, when my family was going through a difficult time, she extended a timely helping hand to me.

But what really inspired me to write about her was what I learned in 2004, when Ruling shared with me what had happened in the scientific research field of high-temperature superconductivity between the end of 1986 and the beginning of 1987. In a Contest of the Century, researchers in physical and material sciences from all over the world broke the high-temperature superconductivity records, one after another. At that time, surrounded by thousands of outstanding male researchers, there were only a few female professionals in this research field, mostly women of Chinese origin, Ruling was the most senior one among them. Moreover, she was the only Chinese scholar who had received a college degree from a university in China and started her career in a research institute in China. She came to the United States when she was over forty. With years of solid academic attainments and unimaginable hard work, she became a world-class materials scientist within a few years, and she was respected by her colleagues at home and abroad. From 1981 to 1997, she was among the 500,000 authors of scientific papers in the world and became one of the 1,000 most-cited published scientists and the first female author in the field of superconducting materials. In addition to admiration for her, I was extremely curious about such a friend who has stories.

In 2005, I had more than 20 hours of in-depth interviews with Meng and wrote a 12,000-word article in Chinese based on our discussions, later edited by her and partially published on a local website. But that was far from what we had envisioned: to provide a faithful snapshot of a specific moment in the history of physical and material sciences. Both of us were busy working full-time then, and I also needed time to digest the many new concepts in superconductivity research and to learn the unfamiliar terminology in material sciences involved in the article. My goal was to organize the wonderful moments that Ruling wanted to share with the world into a coherent story that non-professional readers can understand and want to read. For this reason, our writing plan was put on hold until 2017, after I officially retired and after Ruling’s solo amateur artist exhibition closed. In May 2018, I received the first batch of drafts sent by Ruling via email, and we started our hard work together. In the following three years, we had nearly a hundred discussions and debates, and many new chapters were added after more than a dozen revisions. The first manuscript in Chinese was completed by the end of 2020.

Thanks to the joint efforts of many friends, the Chinese edition of this book was published in April, 2021. Some of Ruling’s friends reviewed the book, making hundreds of comments and modifications, ranging from the main event timeline and participant information to the Chinese translation of English scientific and technological terms and names. Dr. Zihong Zhang, our common friend, was put in charge of the layout and illustrations of the book. Because Ruling and I were inexperienced in manuscript writing and editing, we frequently revised the manuscript after typesetting. Zihong not only made and updated the plates in a timely manner more than ten times, but also made suggestions for selecting content, handling appropriate expression of concepts and emotions, as well as finalizing the English manuscript. Ms. Mei Li, who was the last to join the editorial board for the Chinese version, was expected to proofread words and sentences using her experience working for her church in recent years. However, after carefully reviewing the content of the manuscript, she proposed to divide the technical and social contents of the book into two parts, one focusing on scientific issues, and the other on sociological issues. She also made specific suggestions to highlight the theme and special features of the book.

Some mistakes in the Chinese version have been corrected in the English version. My sincere thanks go to the many friends who made their unique contributions to the English version of this book, including but not limited to the following: Mr. William Nisbett, with a BS degree in Chinese Language and a MS degree in Physics from the University of Houston, participated in the English translation of the second part of the book. Working for a high-tech company then, he used his spare time to finish the translation in just two months, thanks to his fine understanding of the Chinese language and culture. Dr. Wei, Li, a retired professor of English Language and Literature from Lone Star College, translated the most challenging chapters of this book due to their scientific and technological difficulty. He also reviewed and revised the other chapters’ English translation to ensure the English translation conveys the original ideas of the Chinese author faithfully. Mr. David Ross, a professor of English and English as a Second Language at Houston Community College, worked as the English editor and proofreader of the entire book. His professional standard and dedication guaranteed smooth reading and easy comprehension by English-speaking readers. Finally, Danqing Bei, David Ross’s wife, helped in translating all the captions of figures and photos.

In addition to the editorial committee, friends who provided selfless help and enthusiastic encouragement for Chinese and English versions of this book include: Miss Peiheng Zhu, who proofread all chapters of the Chinese version word by word; Dr. Jieqiang Guo, who revised the first draft of two chapters in Chinese; Meng’s colleagues far away in China, Mr. Nengzhong Ye and Mr.  Ruxing Wu, as well as friends in Houston, Drs. Jianguang Wang and Jianjun Jiang, took time to read the entire book or relevant chapters in Chinese and provided valuable feedback. Professor Sharron Wen, Chair of the Chinese Language program of the Department of Languages at the University of Houston, gave her full support by recommending her best student in Chinese Language, Mr. Nisbett, to join the translation work.

I would like to quote a sentence from the book to end my introduction:

I hope that in the year 2100, when our descendants open the ‘National Millennium Time Capsule’ in the ‘National Museum of American History’, and take out those five-centimeter diameter Yttrium-Barium-Copper-Oxide high temperature superconductors, they will be able to recall the stories this book tells and the contributions made from so many heroes behind the scenes.

Jianjun Zeng（Ph D, Geology）

Sept. 15, 2022 in Houston.

Contents

Acknowledgement

Editorial Note

Contents

List of Figures

List of Tables

Part I: High Temperature Superconductors and Me

Prologue

Chapter 1: I Changed my Career Twice

First foray into superconducting materials

Returning to the research National Team

Building a thin film lab

A surprise invitation

Chapter 2: My Promise at the Starting Line

Starting from scratch

First victory

No pain no gain

Chapter 3: Days of Challenging 97K

Returning to Houston

Proving the 35K oxide superconductor

Superconducting transition at 52.5K under pressure

Materials Research Society Annual Meeting in Boston

Optimizing process to make superconductors

Element substitution

Mystery of yttrium

A news conference

Identifying the structure of the new high temperature superconductor

Cranking on all cylinders: discovering a series of rare earth high Tc superconductors

American Physical Society (APS) Annual Meeting

Notes

Chapter 4: New Frontiers

The emergence of new superconductor series

Finding the synthesis mechanism for Hg-base superconductors

The first defect-free C60 single crystal

Applications of high temperature superconductors

Large dimension bulk and rod superconductors

Fabrication of mercury superconductor tape

Fabrication of bismuth superconducting tape

Notes

Chapter 5 Inside and Outside the Media Halo

Changing a bird shotgun for a cannon

Heroes behind the scenes

The Little United Nations of the Superconductivity Center

The fame of a general is built upon the ashes of millions of dead soldiers

Chapter 6 Our Patent

He applied for a patent for Us

An eighteen-year-old mystery

Requesting internal mediation

Ripple effects？

Lawyer’s evidence

Nine years of difficult road of rights protection

Who is the co-inventor of the patent?

Thoughts on the Time limitations of legal action

Who’s to judge?

Photos

Part 2: A Life on Two Sides of the Ocean

Prologue

Chapter 1: Growing up and Schooling

My father and mother

A tomboy hiding from the Japanese

A young girl’s dreams of becoming a writer

From a young Miss to a country girl

Toward becoming a STEM girl

University life

The great calamity of the Cultural Revolution

Notes

Chapter 2: My Forty-Year American Journey

Flying to the new continent

My Chinese colleagues from the Physics Department of UH

The helping hands of overseas Chinese

American friends

The shadow of the FBI

Chapter 3: Different Worlds

The rigor of the Germans

The tolerance and taste of the French

The pragmatism of the Japanese

Italy’s famous brand

Chapter 4: The Wide-Open World Outside of the Lab

Serving the community

Giving back to my Alma Mater

Starting an offshore wind power plant

Promoting the application of high-temperature superconductors

Singing, drawing, and fundraising for the scientific research innovation award

List of Figures

Figure 1. IBM's result was replicated by our lab: Variation of the superconducting transition temperature of Lanthanum Barium Copper Oxide (LBCO) under pressure

Figure 2. The optimized process flow for the preparation of LBCO was summarized from the above records at the end of December 1986

Figure 3. Variation of superconducting transition temperature of Yttrium Barium Copper Oxide (YBCO) compound with superconducting transition temperature higher than 90 K was obtained for the first time under strong magnetic field

Figure 4. Crystal structures of low-oxygen and high-oxygen YBCO. (a) The crystal structure of low-oxygen YBCO is tetragonal. (b) the crystal structure of high-oxygen YBCO is orthorhombic

Figure 5. Process conditions for rare earth element substitution experiments

Figure 6. Development history of superconducting materials

Figure 7. The superconducting transition temperature of Hg 1223 superconducting material is as high as 164 K at 300,000 atmospheres! This is the highest world record in superconductors

Figure 8. Defect-free C60 single crystal grown in 1991

Figure 9. The Textured YBCO block we grew

Figure 10. Furnace temperature gradient profile for growth of YBCO long rods by zone melting

Figure 11. Representation scanning electron micrographs of (a) transverse (b) longitudinal. Fracture surface of YBCO bar together with X-ray diffraction patterns

Figure 12. Houston Chronicle: Paul Chu (right) showed the 6-centimeter-long YBCO rod produced by Meng, Ruling (left), a senior scientist of the team, to the newspaper reporter

Figure 13. Scanning electron microscope image showing the pattern of mercury ribbon growth. (a) mercury tape surface had step-waves wave-like morphology, indicating orderly oriented during a fast crystal growth. (b) the small hole contained HgCa2 which supplied mercury for formation of H-1223

Figure 14. Proceedings of the American Academy of Sciences on May 30, 1988 (a) Journal, front page (b) Journal article

Figure 15. Photos from National Geographic in Inventors and Discoverers—Changing Our World, (a) Nobel Laureates Dr. Müller and Dr. Bednorz, (b) Author and her student

Figure 16. The *866 patent cites my 90K YBCO heterophasic compound prepared with the 214 structure

Figure 17. The *866 patent cites my 90K YBCO single-phase compound prepared with a proportion of 123

Figure 18. The *866 patent cites my experimental record in the section Separation of the green and black phases with the initials of Prof. Ignatiev

Figure 19. The *866 patent’s discussion on rare earth element substitution is based on my experimental notes

Figure 20. Analytical X-ray plot of my sample dated January 12, 1987 cited in the *866 patent

Figure 21.  The painting Gathering Firewood

Figure 22. China and the United States co-host academic and teaching seminars

Figure 23. Deputy Consul General Zhao, Yumin congratulated me on my birthday at my solo exhibition held by the Chinese Association of Professionals in Sciences and Technology (CAPST)

Figure 24. Group photo with members of the CAPST participating in the art exhibition. In second row, the first left is Zhang, Zihong, the seventh from the left is Zhu, Peiheng, and the eighth from the left is Zeng, Jianjun

List of Tables

Table 1. Lattice parameters and critical temperatures of samples with ABa2Cu3O6+x structure.

Part I: High Temperature Superconductors and Me

Prologue

An historically unprecedented competition took place in the world of science from late summer/early fall of 1986 to early spring of 1987. The goal of the competition was to explore new high temperature superconductors. It started with the leading work by two IBM Zürich Research Laboratory scientists, K. Alex Müller and Johannes Georg Bednorz, followed by thousands of physicists and material scientists, mainly in the U.S., China, and Japan, who relentlessly challenged the world record of high temperature superconducting transition temperature (Tc). Tc had been stagnant and stayed around 23K for over 3 decades. When the dust settled, the Tc record had been pushed well above 77K, which is the Tc of liquid nitrogen. As a key member of the University of Houston Low Temperature High Pressure (LTHP) Superconductivity Research Group, as well as the initiator and manager of its Superconducting Materials Laboratory, I was not only a direct eyewitness to these historical events, but was also intimately involved.

This unprecedented competition caught the attention of the scientific world at large for two obvious reasons. There was the lure of a Nobel Medal as the ultimate prize. There was also the enormous potential for commercial applications. With these two incentives at play, the level and intensity of competition among the two hundred sixty plus research groups and laboratories were astonishingly eye-opening. At times, both the duration to maintain a lab’s edge in world ranking and the time window to claim patent priority were counted in days or even in hours. In our lab, I clearly remember that in our attempt to make 98K superconductors, my colleagues and I spent countless sleepless nights. During that period, my lab notes and records on the design and synthesis of different high temperature superconductors would make a 3 to 4ft high pile if stacked.

A conspicuous aspect of this historical competition is the role played by scientists of Chinese heritage. With over 70% researchers and post-doctors being Chinese, my lab, the University of Houston group led by Professor Ching-wu Paul Chu, together with the group in the University of Alabama led by Professor Mau-Kuen Wu were the very first to report on the discovery of the Yttrium-Barium-Copper-Oxide superconductor at 98K. This catapulted us to the top of the world in the high temperature superconductivity competition at the time. In my struggle in the lab, in our collaboration with scientists from other labs who still potentially could be our competitors, I observed Chinese-American scientists’ perseverance and humility, strength and even weakness. I saw successes under the limelight, but also befriended a lot of behind-the-scenes contributors well outside of the limelight. My more than thirty years of hard work in the superconductor field, coupled with the nine plus years of a patent lawsuit, greatly enhanced my initially limited social and humanities knowledge. Together they enhanced my perception of both perfection and flaws in human nature.

Over the years friends and colleagues have continually encouraged me to write down my observation of the discovery and history of high temperature superconductors from 1986 to 1987. I hesitated for two reasons: first, I felt that my expertise was in material science, not humanities or sociology. Now it was my time to relax and enjoy my retirement years with family, more the reason not to pick up those buried difficult memories. Second, I was waiting for better timing to get to the bottom of things and let the dust settle. Before one can comment on events that shook the scientific world, both spatial and temporal distances were clearly justified.

Then in 2017, one of my old colleagues in the Institute of Physics of the Chinese Academy of Science (CAS), Mr. Dianlin Zhang sent me a one-hundred-plus-page-long article by Mr. Wenpu Du on the topic of history during this period. Mr. Du was the science and technology consul in the Chinese Consulate General in Houston from 1986 to 1987. As an observer of the superconductor competition, he actually captured some details about the discovery of high Tc and what happened in the US and China. Much of his paper centered on the work from our University of Houston research group. Understandably there were discrepancies between his description and my own direct experiences since he was not directly involved. Also in 2017, one of the Chinese media in Houston published part of Jianjun Zeng’s interview with me. However, in that interview, I barely touched upon a few historical competition events. This led to my feeling that as a key player in these historical events, it was my duty to set the historical record straight. After all, those events once excited waves in the scientific community, had an everlasting impact on the world of superconductivity, and forever changed some people’s lives.

Because I was personally in the swirls of those waves, though I had been out of these swirls for over a dozen years, I strove to write down my first-hand experiences objectively and truthfully, using my lab notes and records, my published papers, legal documents, and published media as my references. Certain aspects of my writing have never been exposed to public before. Still, what I could disclose would still be far from complete. It is my sincere hope that this book of mine can give the reader a hint of the flavor of the historic scientific competition, drawing a small tree from a large forest.

Chapter 1: I Changed my Career Twice

It was the year 1958. I graduated from the Central South University of Mining and Metallurgy located in Changsha City, Hunan Province in China. After graduation, I got a position as a teaching assistant. Back then, new college graduates had their jobs assigned by the government. Generally, the few graduates with the best records were kept by the institute as teachers. Others were assigned to different research institutes in the Chinese Academy of Sciences (CAS). Those with somewhat inferior records were assigned to posts in factories and mines. In 1958, the universities were undergoing education reform: established professors were chased off the lecture podiums. Instead, young recent graduates were required to teach. So, every day, I had to face a class of students some of whom were older than I was, repeat the text book, and teach Mineral Analysis class. Feeling a lack of deep understanding of the subject matter and a lack of practice, and realizing that the learn-then-teach approach was insufficient, I had to burn a lot of midnight oil, prepping lessons and lecture notes. This continued until I was transferred to Changsha Mining and Metallurgy Research Institute (CMMRI) of the CAS, where I started metallurgical research. In 1974, I started research in superconducting materials. This was followed by my transfer to the Institute of Physics of the CAS where I formally started my career in superconducting materials research.

First foray into superconducting materials

Back in 1960, just when I was getting familiarized with my work on a university lecture podium, I was informed of a decision that totally baffled me: Professor Xi Zhong in the Beneficiation Department at the Central South University of Mining and Metallurgy wanted me to transfer out of the university!

Hurriedly I tried to find out what was going on. It turned out that Professor Zhong had recently been transferred to CMMRI of the CAS as head of a research lab. He planned to create a group for agglomeration research. He knew that two years before my graduation, I had studied agglomerate sintering theory under Russian experts. I also had some hands-on experience during my training at Anshan Iron and Steel Company. That was why he petitioned the university to transfer me out of the university into his group. Furthermore, I learned that CMMRI was a national level institute of CAS; its research covered all major fields in mining, beneficiation, and metallurgy. The heads of its labs were all PhDs highly trained in the then U.S.S.R. Research staff were all high achievers graduated from various universities. Such a research institute would definitely provide good opportunities for my scholarly growth. So, bringing a new graduate with me, I left the university lecture podium and arrived at the CMMRI, joined work on establishing an agglomeration sintering research group. It never occurred to me at the time that it was the start of a long and winding forty-seven-year career in material science.

Within the Mining and Metallurgy Institute, there were three research laboratories: Mining Research Lab, Beneficiation Research Lab, and Metallurgy Research Lab. Research topics included selecting desirable metallic components from mined ores through screening, separating, and purifying by various processes. The institute was tasked with carrying out research projects on heavy metal materials with significant national interests. As such it boasted a complete set of labs with capabilities in chemical analysis, material composition and characteristics, etc. Unfortunately, within two years, the agglomeration research group I helped to setup died a slow death. So now once again, I faced another career change. During that period in Chinese history, everyone was instilled with the idea that it did not matter what one’s major was, or where one’s assignment was after graduation; if needed one must sacrifice one’s own development and expertise so as to treat the Communist Party’s need as one’s own desire. And the research direction at the time was like the lunar cycle: it could be anywhere between a full moon and a waning crescent. At times the emphasis was on application so everyone jumped onto research topics on application; our agglomeration sintering research was such an example. Other times, the emphasis was on basic research. In this case the sintering application research was completely slashed off the list.

Consequently, I was transferred to the metallurgy lab. This was the second time that I changed career (the first was changing from beneficiation to agglomeration). This time around, my main research topic was the structures and properties characterization of rare earths and their alloys, as well as their synthesis processes. Through this research, I learned methods and processes to separate complex conglomerates of rare earths. I also learned to synthesize new materials using solid-state sintering, zonal melting, and vapor depositing methods. In 1962, I joined research on the isolation and smelting of rare earths niobium and tantalum. Within a year, we successfully isolated rare earth niobium and tantalum. Together with principal investigators, we took some twenty students from the Shanghai Normal University with us to Baotou Iron and Steel Company, did a semi-industrial trial of our research results. In 1964, I participated in zirconium-2 alloy beneficiation task, obtained important rare earth elements essential for atomic fission devices. At the time, this was at the forefront of advanced defense projects. We were the leading edge of the effort. In retrospect, for someone like me who was just starting her research, these career changes were far from detrimental. On the contrary, they exposed me to many different topics in research and applications, which helped me to hone my all-rounded skills in material science.

During 1974, Mr. Qirui Zhang from the Superconductivity Lab at the Institute of Physics of CAS came to the Mining and Metallurgy Institute. He gave a presentation on the low temperature superconductor research in the world and their latest research results. He expressed his hope that researchers like us would collaborate with their superconductor research team. So, starting from 1974, I followed the trend in superconductor research and started to synthesize new superconductors.

So what is a superconductor? Normally based on their capability to conduct electric current, materials can be classified into three categories: insulator, semiconductor and conductor. Materials such as dry wood and ceramics are insulators with very high resistance and are incapable of carrying electric current. Metals such as copper and aluminum are all conductors, with very low resistance and good electric current carrying capacity. Of all the metals, gold and silver have the lowest resistivity, followed by copper and aluminum. A semiconductor has its resistivity falling somewhere between that of conductor and insulator. An example is silicon, ubiquitous in modern day electronics. Even the best metal gold has resistivity greater than zero. In 1911, Heike Kamerlingh Onnes, a Dutch physicist and Nobel laureate, measured the resistance of mercury after he successfully liquefied helium. To his astonishment, he found that at liquid helium temperature of 4.2K, mercury resistance vanished. He found that other metals such as tin also exhibited the same behavior. He created the term superconductivity. Such materials are called superconductors. The temperature at which point material’s resistance vanishes is known as its superconducting transition critical temperature (Tc).

In thermodynamics and in cryogenic research, of course, the ideal coldest temperature is defined as absolute zero, denoted as 0 kelvin, or 0K (K = 0), in honor of the famous physicist Lord Kelvin. In terms of Celsius, 0K is equivalent to 273.15°C below zero (-273.15°C). If normal room temperature is about 23°C, then expressed in kelvin it is 296K in absolute temperature scale. Based on temperature under which certain gas becomes liquid, the very low temperature scales can be divided into 4 thermal zones, starting from absolute 0K, in increasing temperature: liquid helium zone (4.2K and higher), liquid nitrogen zone (77K and higher), dry ice zone (194.5 K and higher) and room temperature (296K or around 300K and higher).

Since Professor Onnes discovered mercury with its superconducting Tc around 4.2K, over sixty years prior to 1986, hundreds of new superconductors had been discovered, with ever so slightly increasing Tc. Roughly, Tc increased at a rate of about 0.25K/year. Early superconductors were pure elements. By 1932, more than 50 superconducting metals were discovered, including lead, tin, indium, tantalum, titanium, and niobium. By 1953, superconductors were found in alloys and transition metal carbonates and nitrates. By 1973, a series of intermetallic compounds were discovered to have Tc between 18K and 23K, such as V3Si, V3Ga, Nb3Sn and Nb3Ge. Even though they reached the highest, 23K, they were still in the liquid helium low temperature zone. So they are all called low Tc superconductors.

The discovery of superconductivity initially caused an enormous excitement. Imagine that if resistance of all electric power transmission lines was zero, there would be no loss in power transmission. Household electric utility costs would be greatly reduced. Some people had even dreamed about the idea of perpetual machines in the past. Unfortunately in reality, the