We investigate the magnetic structure of Mn3-xFexSn2 using neutron powder diffraction experiments and electronic structure calculations. These alloys crystallize in the orthorhombic Ni3Sn2 type of structure (Pnma) and comprise two inequivalent sites for the transition metal atoms (4c and 8d) and two Sn sites (4c and 4c). The neutron data show that the substituting Fe atoms predominantly occupy the 4c transition metal site and carry a lower magnetic moment than Mn atoms. Four kinds of magnetic structures are encountered as a function of temperature and composition: two simple ferromagnetic structures (with the magnetic moments pointing along the b or c axis) and two canted ferromagnetic arrangements (with the ferromagnetic component pointing along the b or c axis). Electronic structure calculations results agree well with the low-temperature experimental magnetic moments and canting angles throughout the series. Comparisons between collinear and non-collinear computations show that the canted state is stabilized by a band mechanism through the opening of a hybridization gap. Synchrotron powder diffraction experiments on Mn3Sn2 reveal a weak monoclinic distortion at low temperature (90.08 deg at 175 K). This lowering of symmetry could explain the stabilization of the c-axis canted ferromagnetic structure, which mixes two orthorhombic magnetic space groups, a circumstance that would otherwise require unusually large high-order terms in the spin Hamiltonian.
Theoretical evaluation on the temperature dependence of magnetic anisotropy constants of Nd2Fe14B - Effects of exchange field and crystal field strength -
Magnetic properties of Ruddlesden-Popper phases Sr$_{3-x}$Y$_{x}$(Fe$_{1.25}$Ni$_{0.75}$)O$_{7-δ}$: A combined experimental and theoretical investigation
本文研究了Sr $_{3-x}$ Y $_{x}$（Fe $_{1.25}$ Ni $_{0.75}$）O $_{7-δ}$（$0 \leq x \leq 0.75$）的磁性。在实验上，利用超导量子干涉仪（SQUID）磁强计和中子粉末衍射（NPD）研究了磁性。这是补充的理论研究的基础上密度泛函理论以及海森堡交换参数。实验结果表明，随着Y浓度和O占有率的增加，Néel温度（$T_N$）增加。NPD数据显示所有样品在低温下都是反铁磁有序的，这已经被我们对所选样品的理论模拟所证实。我们的第一性原理计算表明，由于有限的层间交换耦合的三维磁秩序是稳定的。后者产生了一个有限的层间自旋相关消失以上的$T_N$。
Increase of magnetic hyperthermia efficiency due to dipolar interactions in low anisotropy magnetic nanoparticles : theoretical and experimental results
Group theoretical analysis of structural instability, vacancy ordering and magnetic transitions in the system troilite (FeS) - pyrrhotite (Fe$_{1-x}$S)
Theoretical and Experimental Investigation on Structural, Electronic and Magnetic Properties of layered Mn5O8
我们研究了晶体，电子和磁性结构的Mn 5 O 8的最先进的密度泛函理论计算和中子粉末衍射（NPD）测量。该化合物稳定在具有空间群C2/m的单斜晶系结构中，其中Mn离子与氧原子处于扭曲的八面体和三角棱柱配位。当我们考虑到正确的磁结构和库仑关联效应时，基于总能量计算的结构参数与低温NPD测量结果吻合得很好。基于组分之间的晶体轨道哈密顿量布居的键强度分析表明，键行为具有强各向异性，导致其晶体结构的分层性质。采用Hubbard U（GGA+U）的完全相对论广义梯度近似，我们发现Mn_5O_8的磁序为A型反铁磁，易磁化轴方向为[100]，与磁化率和NPD测量结果一致.然而，在不考虑HubbardU的情况下，计算结果将亚铁磁半金属看作是基态，这与实验结果相矛盾，表明该材料中存在很强的库仑关联效应.不考虑库仑修正效应的GGA计算本身足以再现我们在各种Mn位上实验观察到的磁矩。
Spin-Flop Ordering from Frustrated Ferro- and Antiferromagnetic Interactions: A Combined Theoretical and Experimental Study of a $\mathrm{Mn}/\mathrm{Fe}(100)$ Monolayer
An ab-initio theoretical investigation of the soft-magnetic properties of permalloys
本文采用相对论自旋极化K-R电子结构方法研究了Ni_（80）Fe_（20）基坡莫合金。治疗的成分紊乱与相干势近似，我们调查如何磁晶各向异性，K，和磁致伸缩，λ，富Ni的Ni-Fe合金的变化与添加少量的非磁性过渡金属，Cu和Mo。从我们的计算中，我们遵循K和λ的趋势，并找到Ni-Fe-Cu和Ni-Fe-Mo的成分，其中两者都接近于零。Ni-Fe-Cu和Ni-Fe-Mo的这些高磁导率组合物与实验发现的那些很好地匹配。我们监测少数自旋电子的数量，Nmin的磁各向异性的连接。通过人为增加Ni 80 Fe 20的能带填充来提高Nmin，我们能够再现我们在三元合金中发现的支撑磁性软化的关键特征。带填充的影响，磁晶各向异性的原子短程有序的依赖在Ni 80 Fe 20也进行了研究。基于静态浓度波理论的计算表明，Ni-Fe-Cu和Ni-Fe-Mo合金的高磁导率对退火条件的敏感性也强烈地依赖于合金的成分。从这些计算中出现了理想的软磁体。
Theoretical study on magnetic tunneling junctions with semiconductor barriers CuInSe$_2$ and CuGaSe$_2$ including a detailed analysis of band-resolved transmittances
Theoretical Characterization of the Magnetic Properties of Vanadium-doped Ti2C MXenes
Departamento de Ciencias Físicas, Universidad de La Frontera（拉弗龙特拉大学物理科学系）；Universidad de La Frontera（拉弗龙特拉大学）；Facultad de Ingeniería y Arquitectura, Universidad Central de Chile（智利中央大学工程与建筑学院）；Universidad Central de Chile（智利中央大学）
Theoretical Analysis of Electronic and Magnetic Properties of NaV$_2$O$_4$: Crucial Role of the Orbital Degrees of Freedom
利用从第一性原理电子结构计算中得到的实际低能模型参数，我们讨论了正交晶系NaV $_2$ O $_4$的准一维行为的起源，它由共边VO $_6$八面体的双链组成.我们认为，几何方面单独不能解释实验观察到的电子和磁性的各向异性的NaV $_2$ O $_4$。相反，我们将NaV $_2$ O $_4$的独特行为归因于一种特殊类型的轨道排序，它尊重正交$Pnma$对称性。这种轨道排序将所有的$t_{2g}$态分为两种类型：“定域”态和对称的“离域”态，定域态相对于镜面反射$y \rightarrow -$ $y$是反对称的。因此，NaV $_2$ O $_4$可被分类为双交换系统。形成金属带的对称轨道的方向取向似乎足以解释原子间磁相互作用的准一维特征和电阻率的各向异性。
