Electron paramagnetic resonance of Gd 3+ in praseodymium triacetate monohydrate

Abstract

X-band (∼9.6 GHz) electron paramagnetic resonance measurements were carried out on a Gd 3+-doped praseodymium triacetate monohydrate, Pr(CH 3COO) 3·H 2O, single crystal in the temperature range 4.2–295 K. The spin-Hamiltonian parameters were estimated at room, liquid-nitrogen and liquid-helium temperatures by the use of a rigorous least-squares fitting technique. The absolute sign of the zero-field splitting parameter, b 0 2, was determined to be negative by comparison of the intensities of the high- and low-field EPR lines at room and liquid-helium temperatures. The behaviour of EPR spectrum was studied as a function of temperature; the variation of the linewidth and line positions indicated a significant reordering of acetate and water molecules at about 240 K. The present Gd 3+ EPR results in praseodymium triacetate monohydrate are compared with those in the rare-earth triacetate tetrahydrate hosts with Sm, Nd, Er, Y, Yb and Dy ions.