The near future, group of task of Zhang Lei of researcher of center of science of strong magnetic field of academy of science of material of Hefei of the Chinese Academy of Sciences and task of Tian Shaoming of professor of college of Hua Zhongke ability are combined, the magnetic field in La2ZnIrO6 of material of mine of titanium of iridium radical double calcium is revulsive change new headway is gained in research. Relevant research withTricritical Phenomenon And H-T Phase Diagram In A Single Crystal Of The Double-perovskite Iridate La2ZnIrO6For the problem, publish in American physics to learn a magazine " physics comments on B " on.
La2ZnIrO6 is construction of typical mine of double calcic titanium, zn and Ir ion hold the octahedral center position that O place forms respectively, the Ir atom that has 5d electron and the Zn atom that have 3d electron are formed with oxygen atom respectively in all apical octahedral structure, then alternant nest forms structure of mine of double calcic titanium. Because La2ZnIrO6 has very strong spin orbit coupling and rich photograph to change, caused the wide attention of researcher and thorough research. In La2ZnIrO6, as a result of action of strong spin orbit coupling, make its behave the Mott dielectric behavior that is Jeff=1/2 of effective angular momentum. As temperature reduce, below 0 magnetic field, la2ZnIrO6 happens to be transformed in order to the magnetism that turn over iron by paramagnetic when temperature TN~7.5K. Theoretical calculation makes clear, the magnetism ground state of La2ZnIrO6 is the A magnetism that turn over iron, show iron magnetism to arrange inside the layer namely, and the magnetism that turn over iron is shown to arrange between layer and layer.
Researcher undertook traverse to sample of La2ZnIrO6 single crystal. Study to the magnetism with corner through different to sample brilliant, discover La2ZnIrO6 is in Ab direction is isotropy, and very strong magnetism is had in C direction anisotropy behavior. Below 0 magnetic field, la2ZnIrO6 expression is the ground state with the A orderly magnetism that turn over iron. Along A or B direction brings to bear on magnetic field, as outside the addition of magnetic field intensity, the A magnetism that turn over iron evolves to turn over iron magnetism to tilt gradually. Increase magnetic field further, magnetic field destroys the magnetism that turn over iron outside orderly, thereby revulsive a magnetism that turn over iron changes to the photograph of iron magnetism. This one photograph changes to transform unlike the polarization with orderly to magnetism magnetic field, however the magnetism photograph of an one class changes. And in C direction the magnetic field outside bringing to bear on, did not discover magnetic field is revulsive change. Pass pair of magnetic field to study along the magnetic behavior of B direction, compose built La2ZnIrO6 changing on the H-T phasor around. Phasor showed to be in in La2ZnIrO6 A or the rich photograph of B direction changes. In area of low magnetic field, magnetic field makes outside the A magnetism that turn over iron (A-AFM) transfer to tilt the magnetism that turn over iron (C-AFM) . Increase fair threshold value when magnetic field, revulsive gave a magnetism that turn over iron to change to the one stage appearance of iron magnetism (AFM-FM) . Phasor shows, in photograph of iron magnetism photograph, the magnetism that turn over iron and paramagnetic photograph hand in collect place appear to face bound drop threefold (T~8K, h~165Oe) .
The support that this research work gets foundation of science of plan of national emphasis research and development, country, big scientific unit combines fund to wait.
Article link
Graph: ? ╝) the magnetization strength of appearance of form of the crystal structure of La2ZnIrO6, single crystal and different way; (B) H-T phasor and behavior of ternary and critical point
