Magnetic anisotropy and spontaneous magnetostriction of RCuAl (R = Gd, Dy,Ho)

We have studied the magnetic anisotropy and the spontaneous magnetostrictio n of the hexagonal RCuAl (R=Gd, Dy and Ho) compounds by means of X-ray diff raction. A uniaxial magnetic anisotropy in DyCuAl and GdCuAl and a basal-pl ane type of magnetic anisotropy in HoCuAl have been found. The temperature development of lattice parameters revealed a considerable linear spontaneou s magnetostriction both in the basal plane and along the c-axis. The mutual cancellation of these linear effects of opposite sign yields a tiny volume spontaneous magnetostriction. (C) 1999 Elsevier Science S.A. All rights re served.