Magnetic excitations in tetragonal HoCr[sub 2]Si[sub 2].

Magnetic excitations in tetragonal HoCr[sub 2]Si[sub 2] have been measured by neutron spectroscopy. The temperature and Q dependence of the excitations measured at 8 K confirm that they can be attributed to crystal field (CF) dipolar transitions experienced by the Ho ion. The analysis of the neutron spectroscopy data for HoCr[sub 2]Si[sub 2] is simplified by the fact that the CF coefficients have already been determined for the series RX[sub 2]Si[sub 2] (R=rare earth, X=Cu, Ni) by neutron spectroscopy. In addition, electronic band structure calculations and experimental determinations of the electric field gradient for numerous compounds of the type RT[sub 2]Si[sub 2] (T=Cr, Cu, Ni) show that the first-order CF coefficient, A[sub 2][sup 0], changes sign when passing from the series RX[sub 2]Si[sub 2] (X=Cr, Ni) to RCu[sub 2]Si[sub 2]. In the light of this information, the available neutron spectroscopy data for HoCr[sub 2]Si[sub 2] are presented and discussed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]