Magnetic order in Tb2 Sn2 O7 under high pressure: From ordered spin ice to spin liquid and antiferromagnetic order

We have studied the Tb2 Sn2 O7 ordered spin ice by neutron diffraction under an isotropic pressure of 4.6 GPa, combined with a stress of 0.3(1) GPa. Measurements down to a temperature of 0.06 K and up to 100 K probe the effect of pressure both on ground state and spin fluctuation in the paramagnetic region. In the pressure-induced ground state, the ordered spin ice structure with a k0 =0 propagation vector persists, but it coexists with a structure with k1 = (0,0,1). The ordered moment at 0.06 K is reduced, suggesting that pressure also enhances the spin liquid fluctuations at T∼0. In the paramagnetic region, applying pressure changes the short-range spin correlations and suppresses the ferromagnetic correlations. The influence of pressure is discussed considering both isotropic pressure and stress effects.