Neutron Diffraction Investigation of Structure and Magnetic Properties Near the Transition Temperature in La0.7Ca0.2-x□xSr0.1MnO3 (x = 0.05 - 0.01)

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We propose temperature-dependent neutron diffraction measurements on La0.7Ca0.2-x xSr0.1MnO3(x = 0.05 - 0.10) to investigate the evolution of magnetic and structural properties near the Curie temperature (TC). Cation deficiency ( ) in hole-doped manganites introduces Mn2+ alongside Mn3+ and Mn4+, leading to competing exchange interactions and complex magnetic phases. Preliminary data show ferromagnetic behavior at 300 K and enhanced magnetization for x = 0.07, with neutron powder diffraction indicating magnetic ordering changes between 5 K and 300 K. However, current data lack temperature resolution across the transition. Using the GEM diffractometer, we aim to extract atomic positions, site occupancy, magnetic structure, and magnetic moments to understand how Ca2+ vacancies influence phase transitions and magnetocaloric effects. Measurements will be performed on four compositions (x = 0.06, 0.07, 0.08, and 0.09) at ten temperature points (5 - 350 K) in zero field. We request 3 days of beam time to complete the dataset and clarify the relationship between structural disorder, magnetocaloric effect and inhomogeneous magnetic order near TC.

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