By Boris DYAKOV, Cand. Sc. (Phys. & Math.), senior researcher, A. F. Joffe Physicotechnical Institute, Russian Academy of Sciences

On September 23, 1918, a research team under A. Joffe set up physicochemical department within the newly opened State Institute of Roentgenology and Radiology (GRRI). That was the foundation date of the St. Petersburg-based Physicotechnical Institute ("Fiztekh", in 1960 named after Abram Joffe).

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First, the Joffe department had a staff of twenty-five. And as early as 1919 Joffe filed a report about 34 research works accomplished (with the term "X-rays" being used in a third of the number).

Three years later, on November 29, 1921, the GRRI Institute was divided into the research centers (institutes) of medicine and biology, headed by one of its founders, prominent X-ray specialist Dr. Mikhail Nemyonov, of radium studies, headed by the outstanding scientist Acad. V Vernadsky, and of physics, technology and roentgenology (the latter known as the Physico-technical Roentgenological Institute). At last, in 1923, its research staff of sixty-five had their house-warming as they moved into premises of their own. "... The opening of the institute came off just fine," Abram Joffe said in a letter to his wife. "The hall was packed full, and there came many greetings, very warm ones. The furnishings were luxurious, all the rooms already at work. Everybody was amazed at the sight of a perfectly equipped scientific institute, neat and clean. Supper was served in the evening... with cakes, ice cream, fish-in-aspic and even white wine. Tablecloths and dishes we got from the Winter Palace*, while greens, garlands and lampions were our handiwork. Besides, we manufactured three nice chandeliers in the workshops. In a nutshell, the house changed out of recognition in just two weeks...

"The institute is equipped fine, and you can work in it if you turn to..."

Studying solid body characteristics with the use of roentgenography (radiography) was in the mainstream of its work at that time. A. Joffe (in 1920 elected to the Academy of Sciences), assisted by two female research scientists, M. Kirpicheva and M. Levitskaya, and with the participation of L. Termen, used this method for looking into the mechanical characteristics of crystals, and they obtained Laue (X-ray diffraction) patterns** of a rock salt crystal. The Laue patterns showed consecutive stages of the crystal's crushing. These findings were one of the universally acknowledged achievements of the research collective. Another achievement (by a team of Nikolai Davidenkov and coworkers) was the discovery of break of continuity in solid bodies.

These-now classical!-works stimulated studies in reinforcing the strength of many different materials and research in the physics of strength. In the 1930s, A. Alexandrov and S. Zhurkov (subsequently elected to the national Academy of Sciences) developed relevant theoretical findings in their works on glass and quartz reinforcement.

Now what concerns Anatoly Alexandrov. The point is that Abram Joffe drew fresh blood from the Department

* Lev Termen, then on the staff of Fiztekh, was helping to fit out the Hermitage Museum with burglar alarms. Perhaps because of that-and as it was also common practice in those days-the Hermitage (former residence of the czars) supplied the newly founded institute with furniture and other essentials. Even today you may come across pieces of antique furniture in the offices of our main edifice.- Auth.

* Distribution of continuous-spectrum X-ray radiation dissipated by a fixed monocrystal and filmed.- Ed.

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of Physics and Mechanics of Leningrad State University and from other cities too, especially if he found the works of young researchers to be good. In 1925 he invited the physicist Igor Kurchatov (in the 1940s and 1950s, head of the Soviet nuclear project)* and, a few years after, a cohort of researchers from the Kiev Radiology Institute (the men whom Joffe spotted at an Odessa-held congress of physicists in 1930): A. Alexandrov,** and then D. Nasledov, V. Tuchkevich (elected subsequently to the Academy of Sciences), and P. Sharavsky.

I. Kurchatov and A. Alexandrov headed independent and pioneering studies: the former being involved for several years with ferroelectrics***, and the latter-with the physics of polymers.

The year 1932 saw breakthrough discoveries in physics-of the neutron, positron, deuterium; the first artificial chain reaction was realized then too. Besides, the rectifying contact theory was conceptualized on the basis of quantum mechanics ideas of tunneling. Responding to the challenges of the time, Fiztekh ushered in two lines of research: semiconductors and nuclear physics. A. Joffe put I. Kurchatov in charge of nuclear research.

In the 1930s Fiztekh expanded its range of research projects by taking up nuclear isomerism of a bromine isotope and spontaneous fission of the uranium nucleus. Our physicists likewise suggested a nucleon (proton/neutron) model of the atomic nucleus and an electrocapillary pattern of its fission. Meanwhile the Radium Institute, with the active involvement of Igor Kurchatov, had built a cyclotron, and work began on a larger cyclotron at Fiztekh (however, because of the outbreak of the Great Patriotic War in 1941 this work was suspended-the basic units of the setup had to be moved to Moscow where it was commissioned in the end). Our institute, the Fiztekh, commissioned its cyclotron in 1946 (a research team under D. Alkhazov) on which the first microweight samples of plutonium and neptunium were obtained.

But our institute addressed problems well beyond nuclear physics. Here is a brief list of its record in the pre-war years. First, the theory of electronic current in vacuum allowing for Maxwellian rate distribution of electrons (V. Bursian); prediction of a paramagnetic and ferromagnetic resonance (Ya. Dorfman); the kinetic theory of liquids (Corresponding Member of the USSR Academy of Sciences Ya. Frenkel). Besides, our institute pioneered in the discovery of branching chain chemical reactions and in the conceptualization of their theory (Academician Nikolai Semyonov, Nobel Prize, 1956); in the theory of holes-the vacancies in a crystal lattice and in elucidating their role in transfer processes (Ya. Frenkel). Furthermore, our record includes the quantum/ mechanical theory of electronic current diamagnetism (L. Landau); the prediction of an exciton and a relevant theory (Ya. Frenkel); the theory of metal/semiconductor contact rectification (A. Joffe, Ya. Frenkel); the application of statistical physics ideas to heavy nuclei (Ya. Frenkel); the theoretical and experimental studies in non-linear acoustics and in the physics of musical instruments (B. Konstantinov, elected to the national Academy of Sciences in I960)... Our list could be continued.

Any research center in the Soviet Union-even such a well-known one as ours!-could not disclose all of its

* See: Ye. Velikhov, "He Dreamt of a Sun on Earth", Science in Russia, No. 1, 2003.- Ed.

** See: N. Ponomaryov-Stepnoi, "At the Head of the Nuclear Branch", Science in Russia, No. 2, 2003.- Ed.

*** Substances characterized by spontaneous electric polarization in a definite temperature range.- Ed.

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research programs. This is all the more true of defense and special-purpose projects. Now that the archives have been opened, we can do that.

One of Fiztekh's first defense projects (1933) was M. Bronstein's study on determining aircraft velocity in a blind flight. Late in the 1930s our physicists took up such things as "trailless" torpedoes, radar location and ranging, noncontact detonators; also, detection of submarines, anticavitational* protection of screws, armor protection, air navigation, "submarine/aircraft" contact (with submarines under water) and methods of countering such contact if not desirable (say, because of poor visibility).

One of the most difficult and laborious works was tackled by Anatoly Alexandrov and his laboratory, and that was protecting ships against mines (demagnetization) with the use of devices against contactless mines.

Our Fiztekh did a fine job, with flying colors, during the Great Patriotic War of 1941 - 1945. The radio detector and ranger REDOUBT-K (designed and developed by Yuri Kobzarev's team) revolutionized our air defense, while demagnetization of warships under combat conditions made our Baltic, Black Sea, Northern and Pacific Fleets (and the Volga river fleet during the battle of Stalingrad) safe against magnetic mines-not one ship equipped with our system was lost!

In the grim wartime years, Fiztekh- like most of this country's major research centers- was evacuated to the hinterland. While in Kazan, Fiztekh continued its work in an all- out war effort. However, a research team under Pavel Kobeko (elected to the USSR Academy of Sciences in 1943 as corresponding member) stayed on in beleaguered Leningrad. He and his men protected our research premises and outfit, and carried out vital projects, such as determining the strength of ice on Lake Ladoga (the route of the famous "Road of Life" which linked the encircled city with the "mainland" in the harsh winter of 1941/1942); also, they developed a medical drug for gangrene which saved many lives, and took part in demagnetizing warships of the Baltic Fleet.

The Second World War changed the visage of physics. Most of defense projects at Fiztekh were top secret. Judging by the blueprints-declassified recently-this work was wide in scope and high-quality in its level.

This applies in the first place to nuclear physics. The Soviet Union first turned to this field in its practical implications well before the war as a group of Fiztekh physicists on March 5, 1938, sent a letter to the government head Vyacheslav Molotov in which they stressed the need for an appropriate experimental base for further research. Unfortunately, this solicitation did not merit due attention. It was only on the 14th of August 1943 that A. Joffe, upheld by the top echelon of government, issued his historic order of the day whereby the first group of our physicists was moved to Laboratory No. 2 (subsequently, the Nuclear Energy Institute, now the Russian Scientific Center "Kurchatov Institute") for work on the Soviet A-bomb project. We find in this list Abram Joffe himself, 79 researchers from 13 laboratories of our institute as well as 24 fellows of the cyclotron laboratory. Mind you, the total staff of Fiztekh in the initial post-war years was not above 300!

In 1950 Anton Komar was appointed director of Fiztekh. With him in charge, our institute researched in a new scientific trend, the physical gas dynamics, geared to space research and defense objectives. Working in this field, Yu. Dunayev solved the problem of heat shielding of space descent modules and of missile warheads (in 1953 - 1961).

* With reference to cavitation, a process whereby cavities filled with gase(s) arise in a liquid and damage propeller screws, hydro-generators and other pieces of hardware in water.- Ed.

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The birth of high-energy physics spurred wide-ranging research in the physics of accelerators and in neutron physics. Our institute set up a branch at Gatchina (as of 1972, an Independent Institute of Nuclear Physics named after B. Konstantinov, RAS) which commissioned the nuclear reactor WR-M, the best one for that time.

In 1958, on I. Kurchatov's initiative, Fiztekh took up thermonuclear fusion. The first problem to be attacked was hot plasma diagnostics. This work proceeded in a three- pronged effort: corpuscular, superhigh-frequency and optical methods. Special setups- tokamaks (TUMAN-2, TUMAN-2A, FT-1 and FT-2)-were built and commissioned. A large tokamak- TU MAN-3-was put into service in 1980, it was used for conducting experiments on small- and large-radius compression of plasma, and in combination experiments. We are going ahead with research in controlled thermonuclear fusion.

The research trends of the post-war years were further promoted under B. Konstantinov, Fiztekh director from 1957 to 1967. Associated with his name are such novel fields as the separation of light isotopes, controlled thermonuclear fusion and plasma diagnostics, exploration of outer and circumterrestrial space, astrophysics, and so forth.

In the 1960s B. Konstantinov and M. Bredov outlined a program of astro-physical works in keeping with new concepts and subject to experimental verification. The study of micrometeorites in circumterrestrial space (1962 - 1972) punctured the notion of a dense dust cloud around the earth. So space hardware makers did not have to provide for dust protection any longer.

A series of experiments conducted by our researchers on board the space stations ZOND, SOYUZ and KOSMOS revealed sporadic bursts of tritium and helium-3 of solar origin. Thus a new class of solar flares, related to plasmic effects, was detected.

In the early 1970s priority was given to lunar studies, namely to the exploration of the surface of the moon with the aid of moon rovers LUNOKHOD-1 and LUNOKHOD-2. The chemical composition of the surface of the Mare Pluviarum and of Le Monier crater was thus determined.

In those years Fiztekh pushed ahead with paleoastrophysical studies by using the native "archives" of cosmic radiations found in tree trunks, corals, ice and other objects. For example, high-precision measurements of radiocarbon in annual-growth rings of trees produced pioneering results on time-related variations of cosmic radiation fluxes over the preceding 400 years.

As a matter of fact, our institute was always closely involved with theoretical astrophysics. All the way back in the 1920s and 1930s Ya. Frenkel and L. Landau put forward a number of theories in cosmology, nuclear astrophysics and the physics of superdense stars. Radiation equilibrium of stars and the application of the second principle of thermodynamics to the universe were studied by M. Bronstein and L. Landau (1933). In the 1940s our two research fellows, L. Gurevich and A. Lebedinsky, conceptualized a theory on the formation of planets, and looked into the problem of nova and supernova explosions.

Astrophysical studies came to be expanded a good deal in the 1960s. At that time we began in-depth studies into the role of physical vacuum in cosmology and at the initial stages of the evolution of the universe. We also explored in such areas as neutron stars and quasars, reconstruction of the chemical composition of matter and physical conditions of the early universe, the physics of cosmic rays, and so on. And we obtained priority results in all these fields.

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A photocopy of A. Jaffa's order concerning the disposal of the money that went to him with the Stalin Prize. 1942.

Holography had a second birth with us in the 1960s, largely because of the lasers which made much simpler the problem of image representation. Our Fiztekh developed a kit of related fixings-optical elements, semiconductor registration media (vitreous chalcogenides) for holograms, or holographic recording; also, receivers for converters of nonherent light into coherent, photothermoplastic registering devices, photorefractive crystals for vibration analysis, among other novelties.

In 1967 our Fiztekh got a new director, Vladimir Tuchkevich (later Academician), yet another brilliant physicist from the Joffe school. With him in office, Fiztekh zeroed in on the physics of semiconductors and on developing associated instruments. The foundations of such studies were laid back in the 1930s, when our institute elaborated the theory of a "barrier layer" (p-n transition) based on the tunneling mechanism* (A. Joffe, Ya. Frenkel) and defined the separation of semiconductor conductivity into selfadmittance and impurity conductance (V. Zhuze and B. Kurchatov). In those days Joffe was engrossed in the theory of thermoelectricity.

These studies came to encompass all fields of solid body physics known to us and, from the works of individual scientists, developed into research lines and schools in their own right. Here we might as well note the experimental proofs of a quasiparticle, the excition, which gave an impulse to a new trend, the optics and spectroscopy of semiconductors, with Yevgeny Gross (Corresponding Member of the USSR Academy of Sciences) in charge.

All these studies were continued in the 1950s under the guidance of Abram Joffe at the Institute of Semiconductors which sprung from the laboratory he founded. It was there that in 1954 - 1956 the phenomenon of deep penetration of keV ions into semiconductors was discovered, something that stimulated the development of the implantation method which became an effective tool in the production of microelectronic elements.

In the late 1950s and early 1960s Fiztekh undertook works on the magnetism of nonmetals. It was the first to synthesize iron garnets with vanadium and bismuth, and the transparent ferromagnetic RbNiF ₃ . At about the same time we began research into ferromagnetic/antiferromagnetic resonances and spin waves.

Joffe also initiated studies in the physics of unordered systems, and this led to the discovery of a class of vitreous chalcogenide semiconductors which found a wide range of applications in engineering.

Semiconductors meant a revolution both for physics and for human civilization at large to become part and parcel of our life in these 50 and some years. Fiztekh responded by developing this country's first point-contact diodes and transistors (1950 - 1951), high-purity monocrystals of germanium and silicon, junction-type diodes and transistors with n-p transi-

* Passage of a particle (electron in this case) across a potential barrier of quantomechanical origin.- Ed.

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tions (1953), A _III B _v type compounds (1950), the first Soviet junction photodiodes, and power converters-germanium rectifiers for electric currents

Germanium and silicon semiconductor instruments were soon in full-scale production. Further studies showed gallium arsenide to be the most suitable material for making instruments (lasers above all) with exceptional parameters for high-temperature conditions.

In the 1960s, Fiztekh advanced a theory on a double heterostructure laser, that is having a structure with different semiconductors in the contact ("heterotransition"); here a semiconductor with a wide forbidden zone* contains a thin layer of some other semiconductor with a narrower forbidden zone. Under definite conditions a high density of injected carriers is achieved, while the light comes to be fully concentrated in the structure's middle layer which performs the role of a waveguide. Also, we discovered an ideal heterostructure-namely, a self-matched lattice for gallium arsenide in the form of solid solutions of AlGaAs; the above effects occurred there, in this very lattice.

Further search for new heterostructures with reciprocally matched lattices enabled us to obtain diverse heterotransitions for more complex solid solutions; this, in turn, made it possible to vary independently the lattice constant and the width of the forbidden zone. Such techniques made for the appearance of photocathodes, in particular, the fiber-optics communication lasers in the infrared and visible bands.

Everyone now agrees that our Fiztekh scientists spearhead the progress in this area. It is largely due to their efforts that distributed-feedback lasers made their appearance (in which feedback is formed by a diffraction lattice on the waveguide layer surface). Heterostructural studies likewise resulted in the discovery of new basic physical phenomena and made it possible to upgrade as good as all semiconductor devices and develop absolutely new type models.

The present article cannot cover all the achievements of several generations of Fiztekh scientists. Yet one achievement should be mentioned, and this is the result of years and years of research in the development of "semiconductor heterostructures used in high-performance and optoelectronics", which brought a Nobel Prize in physics for 2000 to Zhores Alferov, the present director of our institute.

Illustrations provided by the author.

* Forbidden zone (gap)-a semiconductor's energy spectrum, a zone between valence and conduction bands.- Ed.

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