Magnetoelastic interactions in the orthorhombic RECu₂compounds (RE identical to Tb, Dy, Ho, Er, Tm)

Abstract

A model for the description of magnetoelastic interactions in orthorhombic RECu2 intermetallic compounds is presented and compared with available experimental data on TmCu2 and ErCu2.

Modeling magnetostriction in RCu2 compounds using McPhase

“…The remaining discrepancies ͑e.g., the slope of ⌬b/b and ⌬c/c in high fields parallel a͒ suggest that possibly magnetoelastic CF contributions for lϾ2 are important. Furthermore, the CF model for small strains 4 is not sufficient to describe the giant magnetostriction for high fields parallel c. This is probably due to the importance of large quadrupolar interactions which leads to a magnetic axis conversion. 8 In contrast to the rare earth elements 9 in the RCu 2 series the exchange contribution to the magnetostriction is of the same order as the single ion contribution.…”

The magnetostriction of Tb, Dy and Ho revisited

“…Magnetization isotherms in Ho have been calculated [12] via a self-consistent mean-field method [4] which, including the exchange magnetostriction, has been employed to explain the c-axis distortion as a function of the magnetic field and temperature, as well as the lattice modulation observed in x-ray diffraction experiments [12]. Other kinds of advanced numerical analyses have been performed in RECu 2 intermetallics, where mean-field Monte Carlo simulations [13,14] showed that the exchange and single-ion contributions to the magnetostriction were of the same order of magnitude. This is not the case for other RE elements; for instance, ab-initio calculations in Tb and Er [15] showed that the giant magnetostriction of these elements is dominated by the single-ion 4f crystal electric field (CEF) contribution.…”