A V Jagannadham
Articles written in Proceedings – Section A
Volume 69 Issue 2 February 1969 pp 67-77
The electron paramagnetic resonance of Mn2+ in NaF single crystals is investigated at different temperatures from 573° K to 93° K. Four different spectra designated as I, II, III2 and III4 are observed. Spectrum I consists of a single broad resonance corresponding to precipitated Mn2+ ions. Spectrum II is isotropic and centred near
Volume 69 Issue 6 June 1969 pp 307-315
Electron paramagnetic resonance (EPR) of VO2+ radicals incorporated in face-centred single crystals of NaCl, KC1 and RbCl has been studied in the temperature range of 77° K to 330° K. At liquid nitrogen temperature, anisotropic spectra have been recorded in each case while spectra recorded at room and higher temperatures are isotropic suggesting the existence of a fast readjustment of VO2+ molecular ions in the crystals at higher temperature while this motion gets hindered at liquid nitrogen temperatures. Spin-Hamiltonian constants are calculated from the recorded isotropic and anisotropic spectra. The line widths in each case are found to obey a parabolic law originally proposed by Kivelson. The constants which give a close fit have been evaluated. The random orientation and readjustment of V-0 bond in these alkali chloride crystals is explained on the assumption that the medium exhibits a “liquid-like” nature for VO2+ molecular ion as far as the electron paramagnetic resonance absorption is concerned.
Volume 74 Issue 1 July 1971 pp 34-52
Electron paramagnetic resonance (EPR) of divalent manganese ion has been studied at 9.5 KMc/sec. These studies reveal that Mn2+ ion substitutes at a β-Cs+ site and gets associated with a vacancy at a neighbouring β-Cs+ site in the aft-plane. The