Crystal field effects in rare-earth ferroborates RFe3(BO3)4 with R = Nd, Tb, Dy, or Er

Crystal field effects in rare-earth ferroborates RFe₃(BO₃)₄ with various rare-earth elements are studied theoretically. The rare-earth magnetoelastic interaction Hamiltonian is written in a multipole approximation. The field and temperature dependences of the multipole moments and strain susceptibilities of rare-earth ions in the ferroborate structure are calculated. A comparative analysis of anomalies in the thermal expansion and elastic constants of rare-earth ferroborates with Tb and Dy ions having identical magnetic structure but differing in the degree of anisotropy of the rare-earth ion is performed.     

Magnetic Interactions on Oxide Ferromagnet/Ferromagnetic Intermetallide Interface

Physics of the Solid State - The magnetic properties of heterostructures consisting of two films are studied. The upper layer involves rare-earth intermetallic nanostructured superlattices...     

Algebras of functions on quantum matrix supergroups

M. V. Lomonosov Moscow State University. Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 24, No. 3, pp. 78–79, July–September, 1990.     

Determination of Residual Alkalinity in Positive and Negative Electrodes of a Worked-out Nickel-Iron Battery

The content of sodium carbonate and sodium hydrocarbonate in the active paste of the positive and negative electrodes of a worked-out nickel-iron battery after their prolonged storage in air was determined by means of a conductometric analysis.     

On the dynamic nuclear polarization by the solid effect with phonon bottleneck

The change of phonon temperature at the allowed and forbidden transitions under the solid effect is taken properly into account. It is shown that the phonon bottleneck cannot diminish the nuclear polarization strongly, in contrast to previous theories.     

Study of elastic electron collisions by plasma electron spectroscopy

In this work we study elastic electron collisions by using the plasma electron spectroscopy method, which is based on the study of the electron energy distribution function in a plasma afterglow. We give the results of this method for the electron-electron collision frequency, and the frequency and cross section of the elastic collision of electrons with helium atoms.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 7–11, February, 1987.In conclusion, the authors express their gratitude to Professor N. P. Penkin for useful discussions concerning this work.     

Magnetic properties of the rare-earth ferroborate SmFe3(BO3)4

The magnetic properties of trigonal antiferromagnet SmFe₃(BO₃)₄ are studied experimentally and theoretically. The measured characteristics are considered in terms of a theoretical approach based on the molecular field approximation and a crystal field model for a rare-earth ion. The temperature dependences of the initial magnetic susceptibility and the field and temperature dependences of magnetization in fields up to 5 T are described, and the anomaly in the magnetization curve for B ⊥ c near 1 T, which points to a first-order phase transition, is analyzed.