Excellence in Research: Investigation of novel spin textures in non-centrosymmetric magnetic materials

在大多数固体中，单位晶胞内(x，y，z)位置的每个原子在(-x，-y，-z)位置都有一个不可区分的原子。这些材料称为中心对称材料。然而，中心对称性被破坏的磁性材料，被称为非中心对称材料，由于其在未来纳米级量子信息技术中的潜在应用，近年来引起了人们的极大关注。本项目的目的是用中子散射技术研究非中心对称磁体的基本自旋和晶格性质。中子散射是一种功能强大的探测器，它可以确定非中心对称材料的自旋排列，这将使它们在未来的应用中具有潜在的用途。这项计划中的研究还将培训草原景观农工大学(PVAMU)的下一代研究生和本科生，学习中子散射测量和数据分析。此外，学生还将学习如何生长单晶和低温物理的基本实验室技能。通过联合PVAMU、诺福克州立大学和莱斯大学的力量，将开发一个具有国际竞争力的项目，包括新型复合材料的生长和中子散射。技术摘要该项目专注于非中心对称磁性材料的合成和表征，如ScTMGe(TM=Fe，Mn，Co，Ni，Cu)，掺锰的ScFeGe，以及手性磁性氧化物。端元ScFeGe和ScMnGe均为六方晶系，空间群为P-62M。ScFeGe是一个低于~36K的巡回日象系统，其波矢k=0 0 0.193，磁矩≈0.5 3μB限制在ab平面。当H平行于ab平面时，观察到阈值磁场为≈6.6T的超磁相变。这项研究计划的主要内容是制备上述多晶形式的材料和高质量的单晶，然后对其物理性能进行表征，包括确定其结构、相纯度以及测量其电子和磁性。这项研究的实验结果将揭示材料的结构和磁性之间的相互关系。这些样品是在普莱斯和诺福克州立大学合成的，随后对它们的物理性质进行了表征，包括确定结构，测量它们的电子和磁性。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical abstract In most solids, for every atom within the unit cell at position (x,y,z) there is an indistinguishable atom at (-x,-y,-z). These materials are called centrosymmetric materials. However, magnetic materials where the centrosymmetry is broken, termed noncentrosymmetric materials, have attracted considerable attention in recent years owing to their potential for future nanometer-scale quantum-information technology applications. The aim of this project is to study the fundamental spin and lattice properties of noncentrosymmetric magnets using neutron scattering technique. Neutron scattering is a powerful probe that can determine the spin arrangements of the noncentrosymmetric materials, which will allow their potential use for future applications. The planned research will also train the next generation of graduate and undergraduate students at Prairie View A&M University (PVAMU) for neutron scattering measurements and data analysis. In addition, students will learn how to grow single crystals and basic laboratory skills in low-temperature physics. The joint efforts by combining the strength of PVAMU, Norfolk State University, and Rice University will develop an internationally competitive program involving both the growth of novel complex materials and neutron scattering.Technical abstract This project focuses on the synthesis and characterization of non-centrosymmetric magnetic materials such as ScTMGe (TM = Fe, Mn, Co, Ni, Cu), Mn-doped ScFeGe, and chiral magnetic oxides. Both end members ScFeGe and ScMnGe crystallize in hexagonal crystal structure having P-62m space group. ScFeGe is an itinerant helimagnetic system below ~36 K with wavevector k = (0 0 0.193) and a magnetic moment ≈ 0.53 μB confined to the ab plane. A metamagnetic transition is observed with a threshold field of ≈ 6.6 T when H is parallel to the ab plane. The main element of this research plan is the preparation of the above listed materials in polycrystalline form and high-quality single crystals, followed by characterization of their physical properties, including determination of structure, phase purity and the measurement of their electronic, and magnetic properties. The experimental results obtained from this research will unveil the interrelationships between structural and magnetic properties of materials. The samples are synthesized at Prairie View, Rice, and Norfolk State University, followed by characterization of their physical properties, including determination of structure, and the measurement of their electronic, and magnetic properties.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.