Spin ice and soft spin ice ground state under high pressure: comparative study by neutron scattering

Abstract

We performed high pressure neutron diffraction experiments in two geometrically frustrated pyrochlore magnets. The soft spin ice Tb₂Sn₂O₇ was studied up to 4.6 GPa and down to 60 mK. Its ordered spin ice structure with k ₀=0 propagation vector partly transforms under pressure into a magnetic structure with k ₁=(0 0 1). The reduction of the total ordered Tb moment with respect to ambient pressure suggests that spin liquid fluctuations are also enhanced by pressure. The pressure-induced state is discussed by considering the influence of both isotropic pressure and stress. In contrast, in the true spin ice Ho₂Ti₂O₇, no effect of pressure is observed up to 6 GPa and down to 1.4 K.

Keywords:

• geometrical frustration
• spin ice
• high pressure
• neutron diffraction

Acknowledgements

This experiment is one of the last experiments performed with I. Goncharenko. This article is dedicated to his memory. We thank A. Forget for the sample preparation. H. Cao acknowledges support from le Triangle de la Physique.