Balaji Daneshwaran, Mandlimath Triveni Rajashekhar, Chen Jie, Matsushita Yoshitaka, Kumar Sathasivam Pratheep
Materials Chemistry Research Laboratory, Department of Chemistry, KPR Institute of Engineering and Technology, Arasur, Coimbatore 641407, Tamil Nadu, India.
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan.
Inorg Chem. 2020 Sep 21;59(18):13245-13253. doi: 10.1021/acs.inorgchem.0c01597. Epub 2020 Sep 2.
New langbeinite-type phosphates KPbCr(PO) and KPbFe(PO) are synthesized by solution method and characterized by powder X-ray diffraction, infrared spectra, thermogravimetric and differential thermal analysis, scanning electron microscope, and energy dispersive X-ray analysis. Rietveld refinement reveals that both of the compounds crystallize in the cubic system with 23 space group, and the calculated lattice parameters for Cr and Fe phases are 9.7332(2) and 9.8325(7) Å, respectively. The electron micrographs confirm the crystalline nature of the samples from their surface morphologies. Infrared spectra display the characteristic features of P-O and M-O vibrational bands for both of the phases. Thermal analysis of KPbCr(PO) and KPbFe(PO) indicates that they are thermally stable up to 1273 K. The axial thermal expansion is studied by high-temperature X-ray diffraction between 298 and 1073 K. The average thermal expansion coefficients of KPbCr(PO) and KPbFe(PO) are identified as 8.9 × 10 and 10.8 × 10 K, respectively. Magnetic study reveals both of the compounds follow Curie-Weiss behavior in the higher-temperature region, and antiferromagnetic interactions are dominant.
通过溶液法合成了新型钾镁矾型磷酸盐K₃PbCr(PO₄)₃和K₃PbFe(PO₄)₃，并通过粉末X射线衍射、红外光谱、热重和差示热分析、扫描电子显微镜以及能量色散X射线分析对其进行了表征。Rietveld精修表明，这两种化合物均结晶为立方晶系，空间群为23，Cr相和Fe相的计算晶格参数分别为9.7332(2) Å和9.8325(7) Å。电子显微镜照片从样品的表面形态证实了其晶体性质。红外光谱显示了这两个相的P-O和M-O振动带的特征。对K₃PbCr(PO₄)₃和K₃PbFe(PO₄)₃的热分析表明，它们在高达1273 K的温度下是热稳定的。通过在298至1073 K之间的高温X射线衍射研究了轴向热膨胀。K₃PbCr(PO₄)₃和K₃PbFe(PO₄)₃的平均热膨胀系数分别确定为8.9×10⁻⁶和10.8×10⁻⁶ K⁻¹。磁性研究表明，这两种化合物在较高温度区域均遵循居里-外斯行为，且反铁磁相互作用占主导。
