LOW-TEMPERATURE MAGNETIC-SUSCEPTIBILITIES AND ANISOTROPY OF PR3+ DIGLYCOLLATE CRYSTAL

The results of measurement of magnetic susceptibilities and anisotropi es of single crystals of Pr3+ diglycollate (PrDG), between 300 and 21 K are reported. A change in the sign of the magnetic anisotropy K(para llel to)similar to K-perpendicular to was observed at T = 42 K. In oth er Pr3+ compounds, similar change of sign has also been observed at di fferent temperatures. Such inversion characteristics have been explain ed by the crystal field (CF) effect. The magnetic behaviour of PrDG di d not suggest phase change effect in the temperature range of this stu dy. Magnetic and optical experimental data were analysed considering a very general form of the CF Hamiltonian, allowing for J mixing of 91 \SLJM(J)] states of the 4f(2) configuration of Pr3+, suitably modified under an intermediate coupling formalism, compatible with Pr3+ in the diglycollate host. The best fitting parameters were found to be E-1 = 4730.0, E-2 = 22.16, E-3 = 467.5, zeta = 734.0, alpha = 25.9, beta = -694.0, gamma = 1520.0, B-20 = 145.0, B-40 = -1300.0, B-60 = 650.0, B- 66 = 600.0, B-43 = 1300.0, B-63 = -300.0 (all in cm(-1)). The CF level s of the ground term H-3(4) were determined accurately, which permitte d the calculation of the Schottky specific heat (C-sh) down to 2 K. (C ) 1998 Elsevier Science Ltd. All rights reserved.