High-field magnetization, electric polarization and phase diagram of R2V2O7(R= Ni, Co)
(Phys. Rev. B 98, 184404 (2018), https://link.aps.org/doi/10.1103/PhysRevB.98.184404)
Magnetization plateau describes a quantum state that the magnetization is magnetic-field independent in a finite field range and its value is a fraction of saturation magnetization. Multiferroicity refers to a phase where two or more ferroic orders such as antiferromagnetism and ferroelectricity coexist. Both phenomena have been observed in frustrated aniferromagnets but usually studied separately in different materials.
What did we discover?
We performed magnetization and electric polarization measurements on Ni2V2O7 and Co2V2O7 polycrystalline samples in magnetic fields up to 60 T. We observed half magnetization plateau and ferroelectricity which emerge simultaneously in R2V2O7(R= Ni, Co). The half plateau is stabilized in fields of 8-30 T (7-12 T) for Ni2V2O7(Co2V2O7), whereas two magnetic field induced ferroelectricities are located below and above this plateau. The magnetic phase transitions, theH-Tphase diagrams, as well as the magnetoelectric couplings of these two compounds were further investigated.
Why is this important?
The materials which exhibit both magnetization plateau and multiferroicity are rare because of the strict requirement of their peculiar spin configurations. This kind of material is of particular interest and usually gives rise to a complex magnetic phase diagram. This has been studied, for instance, in the materials CuFeO2 and Ni3V2O8. We demonstrate that R2V2O7(R= Ni, Co) is a kind of new multifunctional material exhibiting both multiferroicity and quantum effect, and believe that these experimental findings improve the knowledge to multiferroics and pave the way for exploring the quantum state of frustrated antiferromagnets.
Why did they need WHMFC?
Pulsed high magnetic fields up to 60 T provide opportunities to explore magnetic transitions, magnetization plateau and field induced ferroelectric phases in R2V2O7(R= Ni, Co). Both high field magnetization and electric polarization measurements can be performed in the WHMFC.
Who did the research?
R. Chen,1J. F. Wang,1,* Z. W. Ouyang,1,†Z. Z. He,2S. M. Wang,3L. Lin,3J. M. Liu,3C. L. Lu,1Y. Liu,4C. Dong,1,5C. B. Liu,1Z. C. Xia,1A. Matsuo,5Y. Kohama,5and K. Kindo5
1Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
2State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
3Laboratory of Solid State Microstructures and Innovative Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
4School of Physics and Technology, Wuhan University, Wuhan 430072, China
5The Institute for Solid State Physics (ISSP), University of Tokyo, Chiba 277-8581, Japan
