Antiferromagnetic resonance in Bi2CuO4

Magnetic resonance of the low-frequency spin-wave branch in the Bi₂CuO₄ antiferromagnet with an easy-plane anisotropy has been studied. Angular, frequency, and temperature dependences of the position and width of the antiferromagnetic resonance (AFMR) line have been measured. Our measurements combined with earlier data [H. Ochta, K. Yoshida, T. Matsuya, T. Nanba, M. Motokawa, K. Yamada, Y. Endon, and S. Hosoya, J. Phys. Soc. Jpn. 61, 2921 (1992); E. W. Ong, G. H. Kwei, R. A. Robinson, B. L. Ramakrishna, and R. B. von Dreele, Phys. Rev. B 42, 4255 (1990) [ have allowed us to determine anisotropy constants of this material and to account for the unusual character of its static susceptibility anisotropy. The AFMR line shifts to the high-field side and broadens in a temperature range of 10–15 K, and the cause of this has remained unclear. In the low-temperature range the line shows a hysteresis corresponding to a static field magnitude several times as large as the spin-flop field. The position and width of the AFMR line depend sensitively on the sample preparation technique. Zh. éksp. Teor. Fiz. 113, 2244–2255 (June 1998)     

Wave beam shaping on diffraction of a whispering gallery wave at a convex cylindrical surface

Institute of Applied Physics, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 31, No. 12, pp. 1482–1487, December, 1988.     

Local momentum-space representation of graviton propagators in an external gravitational field and one-loop counterterms in quantum gravity

Local momentum-space representation of graviton and ghost propagators in an arbitrary external gravitational field is constructed. It is shown that this representation allows to easily obtain one-loop counterterms in quantum gravity.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 50–53, April, 1984.     

The London formula and the product vibrational state distributions of A + BC → AB + C chemical reactions

The vibrational product state distributions of a series of A + BC → AB + C chemical reactions is explained in terms of a simple analytic expression using parameters derived from a London-type formula. The importance of the energy barrier, Sato parameters in determining the vibrational state distributions of exoergic or endothermic chemical reactions is discussed. It is suggested that in many cases it is possible to make accurate predictions, regarding the outcome of a chemical reaction, solely on the basis of the spectroscopy of the separated reactants and products.