INFLUENCE OF PRESSURE AND TEMPERATURE ON THE EPR SPECTRUM OF Gd3+ ION IN Cs2NaLaCl6 SINGLE CRYSTAL

M. Krupski1, P. Morawski1, A. E. Usachev2

1 Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17/19, 60-179 Poznan, Poland,
2 Zavoisky Physico-Technical Institute, Sibirsky Trakt 10/7, Kazan 420029, Tatarstan, Russian Federation

The effect of temperature and hydrostatic pressure on the b40 spin-Hamiltonian parameter for Gd3+ in Cs2NaLaCl6 is studied up to 700 MPa over the temperature range 180-360 K. It was found that 56% of temperature changes in b40 (T) is caused by the spin-photon interaction and the rest 44% is related to thermal expansion of the crystal. The phase transition (Tc = 207 K) from the cubic to the tetragonal phase is a linear function of pressure with the pressure coefficient dTc/dp = (53±0.6) K· GPa-1. Any deviation from linearity has not been observed above Tc.