Pulse-electron paramagnetic resonance of Cr3+ centers in SrTiO3

Electron paramagnetic resonance on chromium doped SrTiO3 samples grown using the Verneuil technique shows the presence of charge-compensated Cr3+-V-O as one of the dominant chromium centers. The spin-lattice relaxation processes have been investigated in samples with both isotropic Cr3+ and Cr3+-V-O centers in heavily doped SrTiO3. The relaxation of longitudinal magnetization was dominated by the sum of two exponentials with two time constants (i.e., a slow and a fast constant) at liquid-helium temperatures. The results of fitting the temperature variation of T-1 suggest that the dominant exponential contribution is related to the spin-phonon relaxation time arising from the local phonon mode. (C) 2013 AIP Publishing LLC.