Biography A Ioffe

In years he studied at a real school. At his end, he moves to St. Petersburg and enters the St. Petersburg Technological Institute, which graduates in the year. Since the year, he has continued his education at the University of Munich under the leadership of one of the best experimenters of that time, the first Nobel Prize laureate in physics, V. during the years of work in the laboratory of X -ray A.

Ioffe performed a number of major studies. These include a precision experiment to determine the "energy power" of radium. The works of A. Ioffe on the mechanical and electrical properties of crystals made in the Munich years were systematic. In the process of their implementation, on the example of the crystalline quartz, he studied and correctly explained the effect of an elastic outcome.

The study of the electrical properties of quartz, the impact on the conductivity of crystals of X -rays, ultraviolet and natural light led A. Joffe to the opening of an internal photo effect, clarifying the limits of the applicability of the OMA Law through the crystal and the study of peculiar phenomena that are playing out in the Elelectric areas. All these works of Ioffe secured his reputation as a physicist who deeply ponders in the mechanisms of the processes he studied and with the exceptional accuracy of conducting experiments, expanding ideas about the atomic-electronic phenomena in solid bodies.

After the brilliant defense of the doctoral dissertation at the University of Munich in the year A. Ioffe refuses to offer his teacher X -ray to stay in Munich to continue joint research and teaching and returned to Russia. Since the year, A. Joffe began work as a senior laboratory assistant at the St. Petersburg Polytechnic Institute. In the physical laboratory of the IOFFA Institute, brilliant work was performed in the years to confirm the Einstein quantum theory of external photoelectric effects, the evidence of the granular nature of the electronic charge, and to determine the magnetic field of cathode rays.

In the year, A. Ioffe determined the charge of the electron, using the same idea as R. Milliken: charged particles of metal in the experience of millikeken - droplets of oil were balanced in the electric and gravitational fields. However, Ioffe published this work in the year Milliken published his result a little earlier, so in the world literature the experiment received his name.

The first work of Ioffe, which compiled the subject of his master's thesis, was devoted to an elementary photoelectric effect and also belonged to the circle of classical research as the work of J. Thomson and R. Milliken to determine the charge of the electron. He proved the reality of the existence of an electron regardless of the rest of the matter, determined the absolute value of its charge, studied the magnetic effect of cathode rays, which are an electron flow, and proved the statistical nature of electron departure with an external photoefficient.

In the year, after the defense of the master's thesis at St. Petersburg University, he was elected an extraordinary professor. For these and some other studies, the Academy of Sciences in the year awarded A. Ioffe by the S. Prize to these most important research cycles A. Ioffe, it is necessary to add two more: one of them is the theoretical work of the scientist dedicated to thermal radiation, in which the classical research of M.

was further developed Another work was also carried out by him in the physical laboratory of the Polytechnic Institute in collaboration with the teacher of this institute M. The work was investigated by the electrical conductivity of ion crystals. The results of studies on the electrical conductivity of ion crystals were subsequently, after the end of the First World War, A.

Ioffe at the Solveevsky Congress of the year were brilliantly reported, caused a lively discussion among its famous participants, and received their complete recognition. At the same time, he became an active member of the physics department of the Russian Physical and Chemical Society, collaborating with the outstanding Dutch theoretical physicist P. Erenfest, who then worked in St.

Petersburg. Moreover, he does not stop the research that had begun in Munich. This period includes its work on the study of x -rays and electrical properties of dielectrics, elementary photoelectric effect and magnetic field of cathode rays, mechanical strength of solids and methods for increasing it. The next extensive study of Iooffe was the continuation of his work performed in the X -ray laboratory.

It was devoted to the study of the elastic and electrical properties of quartz and some other crystals and formed the basis of his doctoral dissertation. Both of these works distinguished phenomenal scrupulousness and accuracy, as well as an invariable desire to reduce all the observed effects into a single harmonious scheme - the features inherent in all students of the Ioffe school.

After defending the doctoral dissertation, Petrograd University, A. Ioffe becomes a professor at the department of general physics. Along with intensive research work, A. Ioffe devoted a lot of effort and time to teaching.He gave lectures not only at the Polytechnic Institute, whose professor became in the year, but also at the courses of P. Lesgft, at the City Courses, at the Mining Institute and the University.

However, the most important in this activity of IOFF was the organization of a seminar in physics at the Polytechnic Institute. It was during these years that A. Joffe, first of the participant, and then the head of the seminar, developed the wonderful style of conducting such meetings that created him well -known fame and characterized it as the head of the school. The Ioffe seminar at the Polytechnic Institute is rightfully considered the most important center of crystalline physics.

A wide outlook and the ability of foresight, the outstanding talent of the scientist and organizer Dali Ioffe, the opportunity to educate a large detachment of physicists, show the importance of physics for technology and national economy. Famous Soviet physicists came out of the IOFF school, many of whom themselves became the founders of their own schools: the Nobel laureates P.

Kapitsa and N. Semenov, academics A. Aleksandrov, A. Alikhanov, L. Artsimovich, I. Kikoin, I. Kurchatov, P. Lukir, I. Obreimimov, Yu. Walter, V. Lashkarev, A. Leipansky, K. Sinelnikov and many others. On the initiative of A. Ioffe, in October, the Physico and Technical Department was created at the X-ray and radiological institute in Petrograd, reorganized in the year at the Physics and Technical Institute, which for more than three decades and headed by A.

he was elected a corresponding member, and in the year-a full member of the Russian Academy of Sciences. Along with the creation of FTI, A. Ioffe belongs to the merit of the organization in the year at the Polytechnic Institute of the Faculty of a new type: Physico-mechanical, whose dean he was also more than 30 years old. The faculty has become a prototype of educational institutions of this type in the country.

The scientific work of A. Ioffe was concentrated in the walls of the FTI, one of which he invariably managed. In years, the main area of ​​work was the study of the mechanical and electronic properties of a solid. In many articles that have left the walls of the FTI in the X years, the surname Ioffe is not among the authors, although his contribution to them is visible to any specialist.

The exceptional scientific generosity of the scientist answered his moral principles and was a component of “art of leading young employees”, about which his student was written by, the Nobel laureate N. Semenov: “If you want the student to engage in the development of any new idea, do it imperceptibly, trying as if he himself would come to his own excessive leadership Students, let them show the initiative as much as possible, to cope with difficulties themselves.

” In the years, A. Ioffe is the chairman of the Scientific and Technical Committee of the Petrograd Industry, in the years-the chairman of the All-Russian Association of Physicists. Another area of ​​research, where IOFFA got important results, is the physics of crystals. In years, he studied the mechanism of conductivity of ion crystals, in the year - their strength and plasticity.

Together with P. Erenfest, he discovered the “quantum” nature of the shifts at this load, which received the theoretical explanation only in the years, and also discovered the phenomenon of “hardening” the material of Ioffe - “healing” of surface cracks. Joffe summarized his works on the problems of solid physics in the well -known book “Crystal Physics”, written based on the materials of the lectures that he gave in the year during a long business trip to the United States.

Ioffe founded an agrophysical institute in Leningrad, which headed up to a year. The beginning of the 19ths was marked by the transition of the FTI to a new topic. One of the main directions was nuclear physics. Ioffe, observing the rapid rise of this area of ​​physics, quickly appreciated its upcoming role in the further progress of science and technology.

Therefore, since the end of the year, the nucleus physics has firmly entered the subject of the works of the FTI. Own scientific work A. Since the beginning of the 10ths, Ioffe has focused on another problem - the problem of semiconductors physics, and his laboratory in the FTI has become a laboratory of semiconductors. The first work in this area was done by Ioffe himself together with J.

Frenkel and concerned the analysis of contact phenomena on the metal border - a semiconductor. They explained the straightening property of such contact within the framework of the theory of the tunnel effect, which developed 40 years later when describing tunnel effects in diodes. Work on the photo effect in the semiconductors led Ioffe to a bold hypothesis that semiconductors are able to ensure effective converting the energy of radiation into electric energy, which served as a prerequisite for the development of new areas of semiconductor technique - creating photoelectric generators in particular, silicon converters of solar energy - “solar batteries”.

These studies laid the foundation in whole areas in the physics of semiconductors, successfully developed in subsequent years by its students. For research in the field of semiconductors in the year A.