Uniaxial pressure effects on spin-ice compound Dy2Ti2O7

We measured the magnetization curve of Dy2Ti2O7 at T = 1.7 K under uniaxial pressure up to 13.0 kbar. The magnetic field (H) was applied along three crystal directions [001], [110] and [111]. Then the direction of applying pressure (P) was parallel to the field direction. For all directions, the magnetization almost saturates at around H = 3 T, and the saturation moment was suppressed with increasing pressure. This pressure-induced suppression of saturation moment can be quantitatively understood by assuming that the lattice distortion is as much as 1 %. For P, H // [0 01], the pressure-induced enhancement of initial magnetic susceptibility was observed, while for other direction, it was suppressed by shrinkage. This enhancement of initial susceptibility for P, H // [001] should originate in some change of the degeneracy in the ground state. (c) 2006 Elsevier B.V. All rights reserved.