进行了B 12二十面体化合物TbB 41 Si 1.2的比热的详细测量。通过浮区法生长TbB 41 Si 1.2晶体。磁化率测量表明,在这些晶体中,在18 K处会出现类似反铁磁的转变。TbB 50和同构TbB 41 Si 1.2是观察到发生磁转变的第一个高硼化物。在20 K以下观察到了比热的驼峰,支持了在该系统中发生磁转变的结论。观察到有趣的磁场依赖性。根据磁化强度测量结果确定,在31 kG的亚磁临界场附近,驼峰移至接近0 K的较低温度。在40 kG时,没有明显的驼峰。但是,在将磁场进一步增加到55 kG和70 kG时,比热出现了新的驼峰,这表明在高磁场下可能存在额外的跃迁。RE B 50(RE的磁化测量= Tb,Dy,Ho,Er)高达55 kG时,表明这些化合物普遍仅在游离稀土离子的饱和磁化强度值的一半左右饱和,这也表明了进一步跃迁的可能性。RE B 50型化合物的结构具有一维特征,稀土
New rare-earth boron-rich compounds with the formula of RE1−xB12Si3.3−δ (RE=Y, Gd–Lu) (0⩽x⩽0.5,δ≈0.3) have been synthesized. They belong to a new type of rhombohedral structure with the space group of R-3m (No. 166) and z=9. The lattice constants were measured from powder XRD data. Crystalstructure solved from powder XRD data for Tb0.68B12Si3 as a representative has been compared with that of YB17
用的式新型稀土富硼化合物RE 1- X乙12的Si 3.3- δ(RE = Y,Gd的路)(0⩽ X ⩽0.5,δ ≈0.3)已经被合成。它们属于一种新型菱形结构的空间群的ř -3米(166号)和Ž = 9。从粉末XRD数据测量晶格常数。晶体结构从铽粉末XRD数据解决0.68乙12的Si 3作为代表已经与YB的相比17.6的Si 4.6(或Y 0.68B 12 Si 3.01),其结构由单晶反射数据确定。通过高分辨率透射显微镜分析确认了结构模型。通过拉曼光谱法测量新晶体的振动模式。通过SQUID测量的RE 1- x B 12 Si 3.3- δ单晶的磁化率与温度的关系表明,它们是低至2.0 K的顺磁性材料。
Single Crystal Growth and Properties of Incongruently Melting TbB6, DyB6, HoB6, and YB6
作者:K. Takahashi、S. Kunii
DOI:10.1006/jssc.1997.7427
日期:1997.10
Details of the singlecrystalgrowth of incongruentlymeltingTbB6, DyB6, HoB6, and YB6using a crucible-free vertical floating zone method are reported. Magnetic susceptibility is reported and discussed. It is suggested that antiferro-quadrupolar ordering occurs in DyB6between 30 and 25.6 K.
Magnetic transitions in B12 icosahedral boron-rich compounds TbB50 and TbB41Si1.2: Lattice constant dependence of the transition
作者:T Mori、T Tanaka
DOI:10.1016/s0925-8388(99)00078-x
日期:1999.6
An antiferromagnetic transition was observed in the higher boride compound TbB50 around the relatively high temperature of 17.5 K. This is the first observation of a magnetic transition in the B12icosahedralboron-richcompounds. In order to investigate the mechanism of the transition, TbB41Si1.2 which is isostructural to TbB50 with larger lattice constants, was synthesized and measured. The transition
Observation of a magnetic transition in the higher boride compound REB50 (RE=Tb, Dy)
作者:T Mori、T Tanaka
DOI:10.1016/s0921-4526(99)02503-x
日期:2000.7
was carried out of REB 50 ( RE = Tb , Dy ) compounds which have a new 9th type of structure of the B12icosahedralcompounds. Measurements of the static magnetic susceptibility of TbB50 at high fields confirmed the antiferromagnetic-like transition previously observed. A similar magnetic transition was also observed for DyB50 at 6.2 K. The REB50-type compounds are the first higher borides in which a magnetic
摘要 合成了新的第9类结构的B12二十面体化合物REB 50 ( RE = Tb , Dy ) 化合物。在高场下对 TbB50 的静磁化率的测量证实了先前观察到的类反铁磁转变。DyB50 在 6.2 K 时也观察到类似的磁跃迁。REB50 型化合物是第一个发生磁跃迁的高级硼化物。转变温度的差异表明 B12 二十面体轴的长度不能作为磁相互作用的唯一考虑因素。
Portnoi, K. I.; Timofeev, V. A.; Timofeeva, E. N., 1965, vol. 1, p. 1513 - 1520
作者:Portnoi, K. I.、Timofeev, V. A.、Timofeeva, E. N.