Magnetic Properties of the RE 2 Pt 6 X 15 ( RE = Y, La–Nd, Sm, Gd–Lu; X = Al, Ga) Series
Magnetic Properties of the
RE
2
Pt
6
X
15
(
RE
= Y, La–Nd, Sm, Gd–Lu;
X
= Al, Ga) Series
复制标题
RE 2 Pt 6 X 15 (RE = Y、La–Nd、Sm、Gd–Lu；X = Al、Ga) 系列的磁性
DOI：
10.1002/ejic.201901332
复制
发表时间：
2020
影响因子：
2.3
通讯作者：
O. Janka
中科院分区：
文献类型：
--
作者：
Mathis Radzieowski;F. Stegemann;O. Janka
RE 2 Pt 6Al 15（RE= Ce-Nd，Sm，Gd-Yb）和RE 2 Pt 6 Ga 15（RE= Y，La-Nd，Sm，Gd-Lu）系列的成员已经由元素通过电弧熔炼然后在感应炉中退火而合成。从单晶衍射数据中观察到Ho 2 Pt 6Al 15与正交（3+1）D正交调制的Sc2 Pt 6Al 15 [Cmcm（α，0，0）0 s 0，α= 2/3]的同型性。衍射图案显示出与原型相同的卫星反射图案，因此改进了相同的调制超结构。观察到[Pt 6Al 15]δ-聚阴离子中Pt和Al原子的完全有序。平均六方结构的晶格参数从粉末X射线衍射实验中得到了改进，并且与这些化合物的先前报告一致。研究了这两个系列的X射线纯多晶样品的磁性。所有研究的化合物的磁化率数据显示实验磁矩接近theRE 3+阳离子的自由离子值和反铁磁/亚铁磁有序在低温下居里温度高达TC = 16.8（1）K的Gd 2 Pt 6 Ga 15。Sm 2 Pt 6Al（15）和Sm 2 Pt 6 Ga（15）在TN = 4.5（1）K（Al）的Néel温度下表现出典型的Vleck型反铁磁有序行为，在TC = 6.5（1）K（Ga）的Néel温度下表现出亚铁磁有序行为。Yb_2Pt_6Al_（15）的Yb原子处于三价氧化态，而Yb_2Pt_6Ga_（15）的Yb原子处于二价氧化态。
The members of theRE2Pt6Al15(RE= Ce–Nd, Sm, Gd–Yb) andRE2Pt6Ga15(RE= Y, La–Nd, Sm, Gd–Lu) series have been synthesized from the elements via arc‐melting followed by annealing in an induction furnace. Isotypism of Ho2Pt6Al15with orthorhombic (3+1)D commensurately modulated Sc2Pt6Al15[Cmcm(α,0,0)0s0,α= 2/3] was observed from single‐crystal diffraction data. The diffraction pattern shows the same satellite reflections pattern as the prototype, therefore the same modulated superstructure was refined. Full ordering of the Pt and Al atoms within the [Pt6Al15]δ–polyanion was observed. The lattice parameters of the averaged hexagonal structure were refined from powder X‐ray diffraction experiments and agree well with previous reports on these compounds. The X‐ray pure polycrystalline samples of both series were studied with respect to their magnetic properties. The susceptibility data of all investigated compounds show experimental magnetic moments close to the free ion values of theRE3+cations and antiferro‐/ferrimagnetic ordering at low temperatures with Curie temperatures up toTC= 16.8(1) K for Gd2Pt6Ga15. Both, Sm2Pt6Al15and Sm2Pt6Ga15show the typicalvan Vlecktype behavior along with antiferromagnetic ordering at a Néel temperature ofTN= 4.5(1) K (Al) and ferrimagnetic ordering atTC= 6.5(1) K (Ga). Yb2Pt6Al15exhibits ytterbium in the trivalent oxidation state, while for Yb2Pt6Ga15a divalent state of the Yb atoms was observed.