Local distortion driven magnetic phase switching in pyrochlore $Y{b}_2(T{i}_{1-x}S{n}_x{)}_2{O}_7$

Abstract

While it is commonly accepted that the disorder induced by magnetic ion doping in quantum magnets usually generates a rugged free-energy landscape resulting in slow or glassy spin dynamics, the disorder/distortion effects associated with non-magnetic ion sites doping are still illusive. Here, using AC susceptibility measurements, we show that the mixture of Sn/Ti on the non-magnetic ion sites of pyrochlore $Y{b}_2(T{i}_{1-x}S{n}_x{)}_2{O}_7$ induces an antiferromagnetic ground state despite both parent compounds, $Y{b}_{2}T{i}_2{O}_7$, and $Y{b}_{2}S{n}_2{O}_7$, order ferromagnetically. Local structure studies through neutron total scattering reveals the local distortion in the non-magnetic ion sites and its strong correlation with the magnetic phase switching. Our study, for the first time, demonstrates the local distortion as induced by the non-magnetic ion site mixture could be a new path to achieve magnetic phase switching, which has been traditionally obtained by external stimuli such as temperature, magnetic field, pressure, strain, light, etc.