The magnetoelectric multiferroic material refers to a kind of multifunctional material that has both magnetic ordering and electrodeposition order. By using two kinds of orderly coexistence and mutual coupling, the magnetic field can be modulated and the electric field can be changed or the magnetic property can be changed by the electric field. In the past decade, multiferroic materials have been a research hotspot in condensed matter physics and materials science because of their rich physical inclusion and wide application prospects. Perovskite oxide is one of the most important material systems for studying ferroelectricity and multiferroicity. In traditional perovskite ferroelectrics, the electrodeization results from the ion displacement leading to a break in the symmetry of the spatial inversion. Therefore, it is generally believed that ferroelectric ordering does not occur in a highly symmetrical lattice such as a cubic lattice with a spatial inversion center. In fact, ferroelectricity has never been observed in the cubic perovskite system. However, in multiferroic materials, the generation of electrical polarization is no longer limited to ion shifts, it can have more diverse origins, and is even closely related to the spin structure; at the same time, the overall symmetry of the system is also due to the symmetry of the crystal and magnetic properties. The symmetry decides together and does not require each to destroy space inversion symmetry. In some special cases, high-symmetry cubic lattices may also exhibit polarization and multiferroic properties. However, so far, people have not yet found a real case of multiferroic cubic lattice with perovskite. Recently, Institute of Physics, Chinese Academy of Sciences/Beijing Key Laboratory of Extreme Condition Physics, National Laboratory for Condensed Matter Physics, Ex6 Group, Longyou Wen, “Hundred Talents Programâ€, Research Fellow, and Associate Researcher M06, National Key Laboratory of Magnetics, Chai Yijun, Researcher Sun Yang and others have made breakthroughs in the study of multi-ferroic properties of cubic lattices. For the first time, a cubic lattice perovskite multiferroic material has been discovered. A-ordered perovskites with the chemical composition AA'3B4O12 provide the possibility of realizing cubic iron multi-crystallinity. In this specially ordered material system, transition metal ions are accommodated at the A' position and the B position at the same time, and a variety of magnetoelectric interactions such as A'-A', A'-B, and BB can be produced. Therefore, by selecting suitable transition metal ions at the A'site and B site, on the one hand, the cubic crystal structure of the material can be maintained, and on the other hand, a specific spin ordered structure can also be formed, and multiferroicity can be induced. A-ordered perovskites are often obtained only under extreme conditions of high temperature and pressure. Long Youwen has long been engaged in the high-pressure preparation of novel A-ordered perovskites. In recent years, he has discovered a variety of novel physical properties of a variety of high-pressure synthesis systems. For example, a magnetoelectric multifunction material system LaCu3Fe4O12 with abnormal negative thermal expansion was obtained under high pressure for the first time [Long* et al, Nature, 458, 60 (2009), selected in the current Nature seal recommendation paper; Mater. Chem. 24, 2235 (2012)]; anomalous electronic system LaMn3Ti4O12 [Long* et al., JACS, 131, 16244 (2009)] and so on. Recently, using the integrated high-pressure and high-temperature preparation system integrated with the research team, Long Yewen’s graduate students Wang Biao and Zhou Long obtained A-ordered perovskite LaMn3Cr4O12 under high pressure and high temperature conditions. The structural analysis shows that the system always maintains the cubic crystal structure of Im-3 in the experimental temperature range (2-300 K). The susceptibility test shows that the material has two antiferromagnetic phase transitions at 150K and 50K. Neutron diffraction further confirms that the antiferromagnetic phase transition of 150K (TCr) comes from the spin order of the Cr3+-sublattice at the B site, and 50K. The antiferromagnetic phase transition of (TMn) comes from the spin order of the Mn3+-sublattice at the A' position. The results of neutron refinement experiments show that both magnetic sublattices have a G-type antiferromagnetic spin structure, and the spin orientation follows the [111] direction of the crystal. In this system, although the Cr-sublattice and the Mn-sublattice alone have non-polarized magnetic space groups, when the two sets of magnetic sublattices are considered as a whole, a polarity can be obtained. The magnetic space group, so as to meet the requirements of the symmetry of the generated electrode. Using the self-developed multi-functional magnetoelectric coupling effect measurement system, Chai Yizheng and Sun Yang et al. tested the dielectric constant and pyroelectric effect of LaMn3Cr4O12 in detail, and found that dielectric constant and thermal release occur at the magnetic order temperature TMn. The sharp changes in electricity and polarisation; when the direction of the applied polarized electric field is reversed, the signs of pyroelectricity and polarisation are also reversed, indicating that intrinsic polarisation has occurred with the appearance of magnetic order. In addition, the applied magnetic field has a significant effect on the polarization and the dielectric constant. Increasing the magnetic field can greatly increase the intensity of pyroelectricity and polarization. At the same time, the change of the polarization depends on the relative orientation of the applied magnetic field and the electric field, showing a strong anisotropic magnetoelectric coupling effect. These experimental results clearly show that the spin order of the Cr- and Mn-sublattices leads to the occurrence of intrinsic polarization. Therefore, LaMn3Cr4O12 became the first multiferroic material system with a cubic perovskite crystal lattice. This study not only achieved important breakthroughs in the preparation of cubic lattice multiferroic materials, but also brought new physics research content. Density functional theory calculations show that the spin-orbit coupling effect of magnetic ions plays a crucial role in the appearance of electrical polarization. However, several existing theoretical models of magnetic ordering to produce multiferroics are not sufficient to explain this. This kind of special multiferroic microscopic origin requires the development of a new multiferroic theoretical model. In addition, due to the absence of ion shift contribution, the electrical polarization of this system may be entirely caused by the abrupt change of the electron cloud, and LaMn3Cr4O12 has also become a typical target for the study of new electronic ferroelectrics. The further exploration of the multiferroic origin and magnetoelectric coupling mechanism of the cubic perovskite may have an important impact on the exploration of new multiferroic materials and the study of new physical mechanisms. The results of relevant studies were published in the recent Phys. Rev. Lett. 115, 087601 (2015), and were selected as PRL Editors' Suggestion. At the same time, they were also selected as the research highlights by the Physics Review News section of the American Physical Society. "Multiferroic Surprise" introduces the topic. The neutron diffraction experiment of this work was done in cooperation with Cao Huibo and Clarina-dela Cruz of the Oak Ridge National Laboratory in the United States; theoretical calculations were done in cooperation with Professor Dong Shuai of Southeast University; Professor M. Azuma of Tokyo Institute of Technology and Professor of Kyoto University in Japan. The Shimakawa research team collaborated to prepare samples for partial neutron diffraction. This work was supported by the Ministry of Science and Youth's "973" project, the Chinese Academy of Sciences 100-person plan project, the National Youth 1000 Project, the National Natural Science Foundation of China, and the Chinese Academy of Sciences Pilot B project. Stainless Wire Mesh Stainless Wire Mesh,Stainless Steel Wire Mesh,Stainless Tray Wire Mesh,Stainless Steel Wire Rope Mesh Anping Deming Metal Net Co.,Ltd , https://www.wovenfence.nl