Showing papers by "Kazan Federal University published in 1977"

Optical Spectra, EPR, and Spin–Lattice Relaxation of Yb3+ Ions in Crystals Having Perovskite‐Type Structure

Abstract: The optical and EPR spectra of centres formed by Yb3+ ions substituted for monovalent and divalent cations are observed on KMgF3 and KZnF3 crystals. From the Stark structure and from the principal values of the g-tensor the crystal field parameters of cubic, trigonal, and tetragonal centres are found. It is shown that as a result of substitution Yb3+ into the Me2+ site (cubic centres) the radius of the nearest coordination sphere increases by 20%. The spin-lattice relaxation time for Yb3+ cubic centres has an unusual temperature dependence of the form T = 82.3T + 1.73 × 10−5T11. [Russian Text Ignored].

NMR Study of Singlet Ground State Systems

Abstract: A review is presented of theoretical and experimental HMR investigations of rare-earth ions in Van Yleck paramagnets carried out since 1956.

Theory of the ESR spectra of Tl2+ ions in K2SO4 single crystals

Abstract: The electron paramagnetic resonance spectrum of β-K2SO4: Tl2+ is considered. The cluster model of the paramagnetic centres is used. It is suggested that the spectrum anisotropy is caused by the crystalline electric field which mixes the state 2P of the Tl2+ ion to the ground state 2S. Such an electric field is absent in the point charge model. An additional proof of the important role of the overlap of the Tl2+ and oxygen ion electron orbits is obtained when analysing the hyperfine structure of the ESR spectrum. [Russian Text Ignored].