Neutron-powder-diffraction study of the magnetic and structural properties of Pr0.6(Ca1-xSrx)0.4MnO3 (0≤x≤1)

We present the results of a neutron-powder-diffraction study in which we have examined the magnetic and structural properties of Pr-0.6(Ca1-xSrx)(0.4)MnO3 (0 less than or equal to x less than or equal to 1) as a function of doping concentration x and temperature. For x less than or equal to 0.15 charge ordering and a Jahn-Teller distortion below 250 K are evident from rapid changes in the lattice parameters and bond lengths as a function of temperature and a transition from a high-temperature orthorhombic to a low-temperature monoclinic structure. For x = 0.0 the system orders antiferromagnetically at T-N = 170 K. At low temperature the system has a canted CLS structure. As the temperature approaches T-N there is a transition to a collinear magnetic arrangement. For Sr doping of up to x = 0.15 the magnetic transition temperature remains almost constant but the magnetic arrangement now has a ferromagnetic component which persists up to T-N. For x > 0.15 the charge ordering is removed and the lattice parameters show a more normal temperature dependence. The materials are now simple ferromagnets and the ferromagnetic transition temperature T-C increases rapidly with x.