Abstract:
This thesis is primary aiming to study the phase transition of ternary antimony oxide systems induced by temperature change and chemical modification. The beamline diffraction techniques, including synchrotron and neutron powder and single crystal diffraction techniques were employed as major techniques to investigate the structural and magnetic properties. The lab instrument techniques, including lab X-ray powder diffraction, UV-Vis, SEM/EDS and PPMS were employed as the first characterization techniques for the planning of beamline experiments. The first antimony oxide system, investigated was Cu1-xCoxSb2O6 (x = 0 to 1). Cu1-xCoxSb2O6 (x = 0 to 1) powder and single crystal samples were studied to investigate a structural and magnetic phase transition behavior. For the structure, it is designed to study a second order transition of CuSb2O6 at high temperature to find a possible intermediate orthorhombic modification which could be revealed by synchrotron powder diffraction and neutron single crystal Laue diffraction technique. Co doping on the A position of CuSb2O6 exhibits a rare type Jahn-Teller transition behavior, based on the temperature dependent synchrotron powder diffraction measurements of Cu1-xCoxSb2O6 (x = 0 to 1) powder samples. The magnetic structure of CoSb2O6 was verified as a canted collinear ordering where the extra Cu doping leads to the rotational behavior of spins, known as a symmetry forced behavior. The second antimony oxide system, investigated was MnTa2-xSb2O6 (x = 0, 0.4, 0.5, 0.6 2). The refined magnetic structure of MnTa2O6 is distinct from a previously published result and the Sb doping on the B position of MnTa2O6 induces to form a tetragonal modification, reported as a meta-stable modification of MnTa2O6 from x = 0.4, 0.5, 0.6. These new tetragonal compounds exhibit antiferromagnetic ordering under the Néel temperature.
