High-pressure-induced spin-liquid phase of multiferroic YMnO3

We investigated the magnetic structure and short-range spin correlations of multiferroic hexagonal manganite YMnO3 by powder neutron diffraction at high pressures up to 6.7 GPa. High pressure induces a spin-liquid phase in multiferroic YMnO3, coexisting with the suppressed long-range antiferromagnetic order. This spin-liquid phase exhibits a temperature dependence distinctively different from short-range spin correlations seen at ambient pressure. Its formation occurs through an in-plane Mn-O bond symmetrization and results in reduced magnetoelastic coupling at high pressures.