Electron Paramagnetic Resonance of Cr4+ in Yx2SiO5

ABSTRACTChromium-doped yttrium orthosilicate Cr:Y2SiO5 was studied by electron paramagnetic resonance (EPR) method at 9.5–9.7 GHz. EPR transitions were observed for Cr4+ substituting Si4+ in tetrahedral sites of Y2SiO5, and orientation dependence of the single crystal EPR spectrum was studied. The ground state of Cr4+ (electron configuration 3d2) in Y2SiO5 is a spin triplet (S = 1). Rhombic symmetry of the electron magnetic dipole-dipole interaction (zero field splitting) leads to three electron spin terms Tx, Ty and Tz in the absence of the external magnetic field. We have observed the magnetically induced anti-crossing of the terms Ty and Tz.We show that in the vicinity of energy level anti-crossing the linewidths and positions of the resonance lines depend on temperature.