OXIDES UNDER EXTREME CONDITIONS: PUSHING THE LIMITS OF NEUTRON DIFFRACTION

The LaCo x Mn 1-x O 3 perovskite series has been widley studied as responses to chemical composition or volume give rise to a variety of electrical and magnetic properties [1].Volume changes can be induced by the application of pressure, which can be used to study structural-property relationships.High-pressure neutron-diffraction experiments have been performed on LaCo 0.9 Mn 0.1 O 3 and LaCoO 3 powders.Neutron powder diffraction is essential to determine the structure of perovskite-like oxides.The high-pressure structural evolution of LaCo 0.9 Mn 0.1 O 3 will be presented [2].The change in tilting angle and strain has been determined upon pressure.This study compliments high-pressure magnetisation measurements, where the Curie temperature shows a strong dependence on applied pressure.A structural study of LaCoO 3 as a function of pressure and temperature using neutron diffraction will also be presented [3].This study is of great interest for its unique temperature-dependent electronic properties.Tha aformentioned experiments have been carried out on the PEARL instrument, the highpressure-dedicated diffractometer at ISIS, STFC [4].We are developing new pressure cells for neutron diffraction to extend the maximum achievable pressure at ISIS.