二维量子自旋系统（CuCl）LaNb 2 O 7具有带隙为2.3 meV的自旋单重态基态，而等结构材料（CuBr）LaNb 2 O 7在TN = 32 K时显示出共线反铁磁有序.本文报道了（CuCl_（1-x）Br_x）LaNb_2 O_7（0 < x < 1）固溶体的合成，并通过磁化率、强场磁化强度和中子衍射研究了其结构和磁性。单元参数的x-依赖性遵循Vegards定律，验证了Cl和Br原子在卤化物位点的均匀分布，尽管从内部和层间单元距离（相对于x）之间的相反相关性推断出更复杂的结构演变。发现5%-Br取代在TN = 7 K时诱导反铁磁有序，与最近的mSR研究一致，并且磁结构是共线的，具有显著降低的磁矩。进一步的Br取代导致TN线性增加至x = 1。这些结果表明（CuCl）LaNb 2 O 7位于量子相界附近。
英文摘要：
The two-dimensional (2D) quantum spin system (CuCl)LaNb2O7 has a spin-singlet ground state with a gap of 2.3 meV, while the isostructural material (CuBr)LaNb2O7 displays collinear antiferromagnetic order at TN = 32 K. Here we report on the synthesis of solid solution (CuCl1-xBrx)LaNb2O7 (0 < x < 1), and its structural and magnetic properties by means of magnetic susceptibility, high-field magnetization, and neutron diffraction studies. The x-dependence of cell parameters follows Vegards law, verifying the uniform distribution of Cl and Br atoms at the halide site, though a more complex structural evolution is inferred from an opposing correlation between the intra- and interlayer cell distances (vs. x). 5%-Br substitution is found to induce antiferromagnetic order with TN = 7 K, consistent with a recent mSR study, and the magnetic structure is collinear, having a significantly reduced moment. Further Br substitution leads to a linear increase in TN up to x = 1. These results indicate that (CuCl)LaNb2O7 is located in the vicinity of the quantum phase boundary.
There currently exist no quantitative methods to determine the appropriate conditions for solid-state synthesis. This not only hinders the experimental realization of novel materials but also complicates the interpretation and understanding of solid-state reaction mechanisms. Here, we demonstrate a machine-learning approach that predicts synthesis conditions using large solid-state synthesis datasets text-mined from scientific journal articles. Using feature importance ranking analysis, we discovered that optimal heating temperatures have strong correlations with the stability of precursor mat…
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Synergetic Enhancement on Bulk and Grain Boundary Ionic Conduction of Mg Doped High-Entropy NASICON-Type Solid Electrolyte for Solid-State Na+ Batteries by Spray Flame Synthesis
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University of California, Berkeley（加州大学伯克利分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Nanyang Technological University（南洋理工大学）
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Unconventional and Powerful Ion Sources for Solid-State Ion Exchange, Cu2SO4 and Cu3PO4: Exemplified by Synthesis of Metastable β-CuGaO2 from Stable β-LiGaO2
First-principles design and subsequent synthesis of a material to search for the permanent electric dipole moment of the electron
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Solid-state reaction synthesis of superconducting refractory-metal germanides for Ge/SiGe quantum devices
QuTech and Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学量子纳米科学卡弗里研究所和QuTech）；Materials Department, University of California, Santa Barbara（加州大学圣塔芭芭拉分校材料系）；Department of Materials, University of Oxford（牛津大学材料系）
Deformation, lattice instability, and metallization during solid-solid structural transformations under general applied stress tensor: example of Si I -> Si II
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