Phase transition of O-orthorhombic LaMn0.95O3.02 at high-temperature

The high-temperature behavior of O-orthorhombic LaMn0.95O3.02 in air was studied by using high-temperature XRD combined with TG/DSC analysis. A phase transition from O-orthorhombic to rhombohedral was found between 573 and 773 K. TG/DSC curves showed a weight gain and no DSC peaks within the temperature range of the phase transition. The phase transition is attributed to the change of oxygen content in LaMn0.95O3.02. The lattice thermal expansion coefficients of rhombohedral LaMn0.95O3.02 were calculated using lattice parameters.