High-Pressure Synthesis of Polar and Antiferromagnetic Mn₂MnMoO₆

Abstract

Polar and magnetic Mn 2 MnMoO 6 with a Ni 3 TeO 6 -type structure (R3) was synthesized at 1673 K under 8 GPa. Mn 2 MnMoO 6 shows a large spontaneous polarization of 65.76 μC•cm −2 , two magnetic transitions at 19 and 47 K, and a strong magnetic frustration factor (f) of 18.4. The polarization reversal barrier is estimated to be 232 meV. X-ray absorption spectroscopy established Mn 2 2+ Mn 2+ Mo 6+ O 6 formal oxidation states. Theoretical calculations indicate an antiferromagnetic ground state of up−down−up−down−up−down spin alignment for Mn ions and a semiconductor characteristic with a band gap around 1.06 eV. Magnetism-dependent dielectric responses show no magnetodielectric and electric coupling, which is attributed to the high polarization reversal barrier and grain boundary effects.

High-throughput screening of stable sulfide semiconductors for solar cell conversion

“…In fact, the energy difference between the collinear and noncollinear magnetic structures is found to be insufficient to modify the overall results. 42,43 In RE 3 BB 0 S 7 (RE = La, Y; B/B 0 = Ti-Cu in the 3d row), we take the cationic arrangements and selected magnetic 3d B/B 0 cations into account to match expected correlations. For the R-P phase Cccm, I4/mmm and P4 2 /mnm, three-type arrangements of the magnetic moments are considered: ferromagnetic (FM) and two antiferromagnetic (AFM) structures, including FM with all moments ferromagnetically aligned, AFM1 with the FM alignment within BS 6 layers and AFM coupling between layers, AFM2 with entirely AFM both within and between BS 6 layers.…”

Thermochemical Properties of High Pressure Neodymium Monoxide

“…Inner shell electrons can then partially participate in bonding, competing with outer shell electrons. Consequently, high temperature and high pressure synthesis methods can be utilized to create compounds, which are metastable at ambient conditions, such as rare earth monoxides (REOs). − REOs exhibit distinct properties from the generally more stable rare earth sesquioxides (RE 2 O 3 ), primarily due to their unique electronic structures . Most REOs crystallize in the cubic Fm- 3 m rocksalt crystal structure.…”