M08-IOP-CAS

Charge, spin and orbital are three degrees of freedom of electron. Up to now, many different electronic devices have already been developed on the basis of the charge or spin property only. However, it is a big challenge on how to couple the charge and spin properties together and realize the mutual control in a single-phase material. By means of the various physical effects of quantum functional materials, one can design a wide variety of electronic devices with special functions. Therefore, how to discover new quantum functional materials with novel quantum effects is extremely important. Because the amount of solid state materials that can be formed under ambient pressure is limited, the extraordinary preparation as represented by high pressure and high temperature has been becoming an effective method to explore new quantum functional materials. Our research group will break through the limitations of ambient-pressure synthesis conditions, find new magnetoelectric quantum functional materials at extended pressure and temperature conditions, tailor their coefficient of thermal expansion (CTE), and study the structure and comprehensive physical properties, reveal the structure-property relationships, and finally provide a crucial material foundation for the application-oriented ME multifunctional devices with controllable thermal expansion.

1. High-pressure synthesis and physical properties of novel magnetoelectric functional materials

In this direction, we will use the irreplaceable advantages of high-pressure and high-temperature extreme conditions to prepare new magnetoelectric functional materials that cannot be formed under ambient conditions, including magnetoelectric multiferroic materials, high-temperature ferro/ferrimagnetic half metals, and high Curie temperature semiconductors, etc.

Representative works:

B. W. Zhou et al., Physical Review Letters 130, 146101 (2023)MORE

Z. H. Liu et al., Advanced Materials 34, 2200626 (2022)MORE

G. X. Liu et al., Nature Communications 13, 2373 (2022)MORE

X. B. Ye et al., Nature Communications 12, 1917 (2021)MORE

L. Zhou et al., Advanced Materials 29, 1703435 (2017)MORE

X. Wang et al., Physical Review Letters 115, 087601 (2015)MORE

Y. W. Long et al., Nature 458, 60 (2009)MORE

2. High-pressure growth and intrinsic physics of large-size magnetoelectric single crystals

Single crystal is the best system to investigate intrinsic physical properties. However, it is a big challenge in the worldwide on how to grow large-size single crystal under high pressure. This direction breaks through the technical bottleneck and develops advanced large-volume high-pressure single crystal growth methods, prepares new magnetoelectric single crystals and studies the underlying physics.

Representative works:

S. J. Qin et al., Chinese Physics B 31, 097503 (2022)MORE

S. J. Qin et al., Inorganic Chemistry 60, 6298 (2021)MORE

Y. X. Liu et al., Physical Review B 101, 144421 (2020)MORE

Y. W. Long et al., Journal of Physics: Condensed Matter 23, 245601 (2011)MORE

3. Multiple manipulations of exotic quantum states

Double-Perovskite

High pressure is not only an important material preparation method, but also a useful manipulation method for quantum states, since in-situ high pressure can significantly reduce the interatomic distance, enhance the orbital hybridization, and expand the bandwidth. In this direction, we will study the exotic magnetoelectric quantum states induced by high pressure and other combined stimuli such as temperature, magnetic field, electric field and light field etc.

Representative works:

Z. H. Liu et al., Journal of the American Chemical Society 142, 5731 (2020)MORE

J. Y. Yang et al., Physical Review B 92, 195147 (2015)MORE

J. Y. Yang et al., Inorganic Chemistry 54, 6433-6438 (2015)MORE

Y. W. Long et al., Chemistry of Materials 24, 2235 (2012)MORE

4. Structure and composition design, thermal-expansion control, and related mechanism of novel magnetoelectric functional materials

Thermal expansion is a longstanding issue for the application of functional materials and devices. The discovery of negative thermal expansion (NTE) materials makes it possible to tailor the overall coefficient of thermal expansion (CTE) of functional materials and devices. In this topic, by taking advantages of our high-temperature and high-pressure apparatus, we focus on the exploring of novel magnetoelectric functional materials with controllable thermal expansion, and related physical mechanism, according to the current research status of functional NTE materials.

Representative works:

H. T. Zhao et al., Small 20, 2305219 (2024)MORE

Z. Pan et al., ACS Applied Materials & Interfaces 14, 23610 (2022)MORE

Z. Pan et al., Chemistry of Materials 31, 6187 (2019)MORE

Z. Pan et al., Journal of the American Chemical Society 139, 14865 (2017)MORE

5. Neutron and X-ray study of magnetic materials

Neutron and X-ray scatterings are two of the state-of-the-art techniques for the studies of microscopic physical properties in magnetic materials. Making use of large scientific facilities such as neutron sources and synchrotron light sources, they can provide valuable information regarding the multiple degrees of freedom for the correlated electrons in condensed matters. In this regard, we use a variety of neutron and X-ray techniques to investigate the magnetic ordering, orbital contributions, and various elementary excitations of magnetic systems. By doing so, we are able to establish the magnetic Hamiltonian of the systems and explore the microscopic mechanisms of their exotic physical properties.

Representative works:

Y. Shen et al., Nature 540, 534 (2016)MORE

Y. Shen et al., Physical Review X 13, 011021 (2023)MORE

Y. Shen et al., Physical Review Letters 129, 207201 (2022)MORE

Y. Shen et al., Nature Communications 10, 4530 (2019)MORE