标题： 磁对分布函数和半极化中子粉末衍射在HB-2A粉末衍射仪上的研究 显示英文标题

标题： Magnetic Pair Distribution Function and Half Polarized Neutron Powder Diffraction at the HB-2A Powder Diffractometer

摘要： 局部磁序和各向异性对于理解量子材料及其以外的物质的基本行为和出现的功能特性通常至关重要。 中子粉末衍射实验和分析工具的进步现在允许进行定量确定。 我们在这里通过在高通量同位素反应堆（HFIR）的HB-2A中子粉末衍射仪上进行的互补总中子散射和极化中子测量来展示这一点。 近年来，磁性对分布函数（mPDF）分析作为一种强大的技术出现，用于探测磁性材料的局部磁自旋有序。 这种方法可以广泛应用于任何磁性材料，但特别适用于研究具有短程磁序的系统，例如维度降低的材料、几何受挫磁体、热电材料、多铁材料和关联顺磁体。 磁各向异性通常支撑着所采用的短程序。 半极化中子粉末衍射（pNPD）可用于确定磁性位点上的局部磁化率张量，以量化磁各向异性。 因此，结合mPDF和pNPD的技术可以提供关于局部磁行为的有价值见解。 这里展示了针对这些技术优化的一系列测量作为示例案例，重点放在短程序占主导地位的受挫材料上，这些包括达到超低温（<100 mK）的测量，这通常不适用于此类实验。 显示英文摘要

摘要： Local magnetic order and anisotropy are often central for understanding fundamental behavior and emergent functional properties in quantum materials and beyond. Advances in neutron powder diffraction experiments and analysis tools now allow for quantitative determination. We demonstrate this here with complementary total neutron scattering and polarized neutron measurements on the HB-2A neutron powder diffractometer at the High Flux Isotope Reactor (HFIR). In recent years, magnetic pair distribution function (mPDF) analysis has emerged as a powerful technique for probing local magnetic spin ordering of magnetic materials. This method can be broadly applied to any magnetic material but is particularly effective for studying systems with short-range magnetic order, such as materials with reduced dimensionality, geometrically frustrated magnets, thermoelectrics, multiferroics, and correlated paramagnets. Magnetic anisotropy often underpins the short-range order adopted. Half-polarized neutron powder diffraction (pNPD) can be used to determine the local susceptibility tensor on the magnetic sites to quantify the magnetic anisotropy. Combining the techniques of mPDF and pNPD can therefore provide valuable insights into local magnetic behavior. A series of measurements optimized for these techniques are presented as exemplar cases focused on frustrated materials where short-range order dominates, these include measurements to ultra-low temperature (<100 mK) not typically accessible for such experiments.