论文标题
抗铁磁Mn $ _ {2} $ PTPD的晶体和磁性结构
Crystal and magnetic structure of antiferromagnetic Mn$_{2}$PtPd
论文作者
论文摘要
我们使用粉末X射线和中子衍射实验研究了Mn $ {} _ {2} $ PTPD合金的晶体和磁性结构。该化合物被认为属于具有晶体对称性$ \ mathit {i} $ 4/$ \ Mathit {mmm} $（tial $ {} _ {3} $ - 类型）的Heusler家族。但是，在这项工作中，我们发现PD和PT原子是无序的，因此Mn $ {} _ {2} $ PTPD在$ \ Mathit {l} $ 1 $ {} _ {0} $结构中具有$ \ Mathit {l} $ 1 $ {} $结构，其结构具有$ \ Mathit {p} $ 4/$ 4/$ \ MATHIT {MMMMMM} $ MMM} MMM {MMM MMM} MMM（MMMMMETRY）二元合金。晶格常数为$ \ Mathit {a} $ =2.86Å和$ \ Mathit {C} $ =3.62Å在室温下。 Mn $ {} _ {2} $ PTPD在Néel温度$ \ MATHIT {T} $ \ MATHIT {} $ {n} $ = 866 K下方具有共线性反铁磁性自旋结构$ \ mathit {ab} $ - 平面。我们观察到$ \ Mathit {t} $$ {} _ {n} $附近的晶格参数发生了很大的变化。该样品表现出金属行为，其中电阻率和载体浓度分别为10 $ {}^{ - 5} $ $ $ $ω$ cm和10 $ {}^{21} $ cm $ {}^}^{ - 3} $。
We have investigated the crystal and magnetic structure of Mn${}_{2}$PtPd alloy using powder x-ray and neutron diffraction experiments. This compound is believed to belong to the Heusler family having crystal symmetry $\mathit{I}$4/$\mathit{mmm}$ (TiAl${}_{3}$-type). However, in this work we found that the Pd and Pt atoms are disordered and thus Mn${}_{2}$PtPd crystallizes in the $\mathit{L}$1${}_{0}$ structure having $\mathit{P}$4/$\mathit{mmm}$ symmetry (CuAu-I type) like MnPt and MnPd binary alloys. The lattice constants are $\mathit{a}$ = 2.86 Å and $\mathit{c}$ = 3.62 Å at room temperature. Mn${}_{2}$PtPd has a collinear antiferromagnetic spin structure below the Néel temperature $\mathit{T}$${}_{N}$ = 866 K, where Mn moments of $\mathrm{\sim}$4 $μ$${}_{B}$ lie in the $\mathit{ab}$-plane. We observed a strong change in the lattice parameters near $\mathit{T}$${}_{N}$. The sample exhibits metallic behaviour, where electrical resistivity and carrier concentration are of the order of 10${}^{-5}$ $Ω$ cm and 10${}^{21}$ cm${}^{-3}$, respectively.
