PAC study of martensitic transformation in R-Cu compounds.

PASQUEVICH A. F; FERNÁNDEZ VAN RAAP M. B.; FORKER M.

PHYSICA B - CONDENSED MATTER

Elsevier

Año: 2007 vol. 389 p. 120 - 123

0921-4526

The martensitic transformation from the cubic CsCl-type to the orthorhombic FeB-type structure of RCu (R= Gd, Tb and Y) compounds has been investigated by perturbed angular correlation (PAC) measurements of the nuclear electric quadrupole interaction (QI) at 111Cd probe nuclei on the Cu site as a function of temperature. The QI data indicate that the martensitic transition extends over a finite temperature range and affects only part of the samples. The transition ranges are 190 K<T<250 K, 80 K<T<150 K and 60 K<T<120 K for GdCu, YCu and TbCu, respectively, with saturation values between 40 and 60 percent. The temperature dependence of the QI parameters in the FeB-type is independent of the R constituent. The order of magnitude of the magnetic hyperfine interaction in the FeB-type structure has been estimated from the low temperature PAC spectra.