ELECTRON-PARAMAGNETIC RESONANCE OF MN-2+ DOPED IN ALKALI TRIHYDROGEN SELENITE SINGLE-CRYSTALS

The electron paramagnetic resonance spectra of Mn**2** plus doped in MeH//3(SeO//3)//2 Me equals Li, Na, K, and Rb) single crystals have been studied at 298 K. In LiH//3(SeO//3)//2, an axis of non-coincidence effect has been observed and Mn**2** plus spectra show line broadening of outer transitions. In NaH//3(SeO)//3//2, Mn**2** plus substitutes for Na** plus ions and is associated with second nearest neighbour Na** plus ion vacancies. Below the ferroelectric phase transition temperature of this crystal every line of the spectrum appears to split into two. The spectra of Mn**2** plus doped LiH//3(SeO//3)//2 and NaH//3(SeO//3)//2 (in paraelectric phase) have been analysed using the spin-Hamiltonian for rhombic symmetry. However, in Kh//3(SeO//3)//2 and RbH//3(SeO//3)//2 the Mn**2** plus ions give only one line. The linewidths and g values of the lines for KH//3(SeO//3)//2 and RbH//3(SeO//3)//2 are determined.