69,71Ga and 139La NMR characterisation of LaGaO3 and La1−xSrxGa1−xMgxO3−x

An NMR characterisation of the perovskite LaGaO3 using the isotopes 69,71Ga and 139La has been used to provide, via measurement of the nuclear quadrupole interaction (NQI), an independent confirmation of the orthorhombic distortion from ideal cubic. The NMR lineshape changes consequent on doping LaGaO3 with 2, 5, 7.5 and 10 mol% of both SrO and MgO to achieve (eventually) the cubic form have been observed and interpreted in terms of a distribution of local electrical field gradients due to substitution on La and Ga sites on the Sr2+ and Mg2+ ions, respectively.