Jiang Jiong, Olmstead Marilyn M, Kauzlarich Susan M, Lee Han-Oh, Klavins Peter, Fisk Zachary
Department of Chemistry, One Shields Ave., University of California, Davis, California 95616, USA.
Inorg Chem. 2005 Jul 25;44(15):5322-7. doi: 10.1021/ic0504036.
A new rare earth metal Zintl phase, Eu(3)In(2)P(4), was synthesized by utilizing a metal flux method. The compound crystallizes in the orthorhombic space group Pnnm with the cell parameters a = 16.097(3) A, b = 6.6992(13) A, c = 4.2712(9) A, and Z = 2 (T = 90(2) K, R1 = 0.0159, wR2 = 0.0418 for all data). It is isostructural to Sr(3)In(2)P(4). The structure consists of tetrahedral dimers, In(2)P(2)P(4/2), that form a one-dimensional chain along the c axis. Three europium atoms interact via a Eu-Eu distance of 3.7401(6) A to form a straight line triplet. Single-crystal magnetic measurements show anisotropy at 30 K and a magnetic transition at 14.5 K. High-temperature data give a positive Weiss constant, which suggests ferromagnetism, while the shape of susceptibility curves (chi vs T) suggests antiferromagnetism. Heat capacity shows a magnetic transition at 14.5 K that is suppressed with field. This compound is a semiconductor according to the temperature-dependent resistivity measurements with a room-temperature resistivity of 0.005(1) Omega m and E(g) = 0.452(4) eV. It shows negative magnetoresistance below the magnetic ordering temperature. The maximum magnetoresistance (Deltarho/rho(H)) is 30% at 2 K with H = 5 T.
通过金属助熔剂法合成了一种新型稀土金属津特相Eu(3)In(2)P(4)。该化合物结晶于正交晶系空间群Pnnm，晶胞参数a = 16.097(3) Å，b = 6.6992(13) Å，c = 4.2712(9) Å，Z = 2（T = 90(2) K，所有数据的R1 = 0.0159，wR2 = 0.0418）。它与Sr(3)In(2)P(4)同构。其结构由四面体二聚体In(2)P(2)P(4/2)组成，这些二聚体沿c轴形成一维链。三个铕原子通过3.7401(6) Å的Eu-Eu距离相互作用形成直线三聚体。单晶磁性测量表明在30 K时存在各向异性，在14.5 K时发生磁转变。高温数据给出正的魏斯常数，这表明存在铁磁性，而磁化率曲线（χ对T）的形状表明存在反铁磁性。热容在14.5 K时显示出磁转变，该转变会被磁场抑制。根据与温度相关的电阻率测量，该化合物是一种半导体，室温电阻率为0.005(1) Ω·m，E(g) = 0.452(4) eV。它在磁有序温度以下表现出负磁阻。在2 K、H = 5 T时，最大磁阻（Δρ/ρ(H)）为30%。
