Electron Paramagnetic Resonance Studies of VO2+ in KNO3 and CsNO3 Single Crystals

The electron paramagnetic resonance spectra of the VO2+ ion doped in KNO3 and CsNO3 single crystals have been investigated over a wide temperature range. Room‐temperature studies reveal that there is a very fast readjustment of VO2+ ion, in both crystals, which is manifested in the presence of a single isotropic octet, thereby exhibiting a low viscous “liquidlike” nature. At low temperatures an anisotropic spectrum is obtained due to the hindered rotation of the VO2+ ion. The effect of CsNO3 in hindering the rotation of a vanadyl ion is found to be greater than that of KNO3. The linewidths at room temperature are found to depend upon the mI quantum number, and an attempt is made to fit the linewidth data of the present study in the theoretical expressions of Kivelson. It is found that Kivelson's theory can qualitatively explain the observed variation of linewidth with nuclear quantum number mI, but the experimental data could not be fit quantitatively into the theory. All the spectra are analyzed using th...