Low-temperature structural phase transition in monoclinic RbDy(WO_4)_2 crystal

摘要

The ESR spectrum of Dy~3+ ion in the low-symmetry RbDy(WO_4)_2 crystal has been studied in the temperature region of T= 4.2÷30 K. The ESR linewidth was found to increase from 130 mT up to the maximum Value of 190 mT at T=9 K and then to decrease down to 150 mT at 4.2 k. The components of the g-tensor change considerably without change of their spatial orientation in the temperature range from 12 K to 7 K: gz = 2.5, gx≈0, gy =1.41 at T> 12 K; gz=1.53, gx≈0, gy=1.2 at T<7 K. The observed λ-shaped behaviour of absorption linewidth and the decrease in the g-factor are assumed to be due to the low-temperature structural phase transition(Tspt≈9K).