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van der Waals (vdW) magnetic insulators are of significance in both fundamental research and technological application, but most two-dimensional (2D) vdW magnetic systems are unstable and of high lattice symmetry. Stable 2D vdW magnetic insulators with anisotropic structure are needed to modulate the properties and unlock potential applications. Here we present a stable vdW antiferromagnetic material, CrOCl, with low-symmetry orthorhombic structure, and investigate systematically its magnetism, phase transition behavior, and optical anisotropy. Spin–phonon coupling effects are uncovered by the abnormal frequency shifts of Raman-active modes, suggesting the formation of a magnetic superstructure. The sizable abnormal change of interplanar spacing indicates the presence of a structural transition at around 27 K. Further in-plane vibrational, reflectional, and absorptional anisotropic properties are explored both experimentally and theoretically, revealing a highly polarization sensitive characteristic and linear dichroism in 2D CrOCl. Meanwhile, the particularly high polarization dependency of the second-harmonic generation and the nonlinear susceptibility of ∼2.24 × 10–11 m/V make it suitable in the field of polarization-dependent nonlinear optics. The findings on the intricate properties of 2D CrOCl lay foundations for future applications of low-symmetry vdW magnets in spin-dependent electronic and optoelectronic devices.

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The new d 10 -d 10 dimer Cu 2 (dppm) 2 (O 2 CCH 3 ) + (as a BF 4 -salt) has been prepared and characterized by X-ray crystallography and by 1 H and 31 P NMR, vibrational, and electronic spectroscopy. The compound is luminescent at 77 K but not at room temperature. MO calculations and geometry optimizations have been performed using the EHMO and DFT models, respectively. In the solid state the Cu 2 separation is 2.788(1) Å where ν(Cu 2 ) ) 87.7 cm -1 , indicating the presence of weak Cu‚‚‚Cu interactions. The MO calculations predict that the lowest energy excited states are MLCT from Cu to phenylphosphine/acetate. These predictions have been confirmed by electronic spectroscopy via a comparison between Cu 2 (dppm) 2 (O 2 CCH 3 ) + and Cu 2 (dppm) 2 (O 2 CC 6 H 5 ) + . In solutions, both NMR ( 1 H and 31 P) and luminescence spectroscopies (time-resolved spectra and τ e analysis) demonstrate the presence of two metal species in solutions: Cu 2 (dppm) 2 (O 2 CCH 3 ) + and Cu 2 (dppm)(O 2 CCH 3 ) + . The dimer crystallizes in the triclinic space group P1 h with a ) 11.572( 2) Å, b ) 12.552(2) Å, c ) 19.543(3) Å, R ) 85.274(12)°, β ) 82.108(11)°, γ ) 68.950(12)°, and Z ) 2.

van der Waals (vdW) materials exhibit great potential in spintronics, arising from their excellent spin transportation, large spin–orbit coupling, and high‐quality interfaces. The recent discovery of intrinsic vdW antiferromagnets and ferromagnets has laid the foundation for the construction of all‐vdW spintronic devices, and enables the study of low‐dimensional magnetism, which is of both technical and scientific significance. In this review, several representative families of vdW magnets are introduced, followed by a comprehensive summary of the methods utilized in reading out the magnetic states of vdW magnets. Thereafter, it is shown that various electrical, mechanical, and chemical approaches are employed to modulate the magnetism of vdW magnets. Finally, the perspective of vdW magnets in spintronics is discussed and an outlook of future development direction in this field is also proposed.

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By using a ligand containing pyridyl and carboxylate groups as units, a novel (3,36)-connected and self-interpenetrated metal-organic framework was constructed, which exhibited high thermal stability and gas sorption capabilities.

This study evaluates the feasibility of two thermal pretreatments including hydrothermal carbonization (HTC) and low temperature pyrolysis (LTP) on the production of Eucommia ulmoides biochar. The waste wood of Eucommia ulmoides Oliver was pretreated and characterized for fuel applications. The results confirm that both LTP and HTC are promising processes for improving fuel properties. However, for the same char yield, the required temperature for HTC is lower than LTP, as the char yields of H 200 and L 300 were quite close (66.50% vs. 66.74%). The surface morphology is significantly different between the pyrolytic carbon and the hydrochar. In addition, it was found that the H/C and O/C ratios of H 300 were 0.82 and 0.21, respectively, and the H/C and O/C ratios of L 340 were 0.77 and 0.22, respectively. They were similar to that of sub-bituminous. Moreover, under the same reaction temperature, hydrochar showed better grindability, hydrophobicity, and reduction in inorganic content. Comparing the integrated combustion characteristic index ( S ), LTP process had the better performance within the lower temperature under 220 °C while HTC process performed better at temperature higher than 300 °C. The results reveal that HTC has the potential to produce solid carbonized products with better fuel quality.