title: Negative magnetoresistance in a magnetic semiconducting Zintl phase: Eu(3)In(2)P(4).
abstract: 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)](6-), 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.
authors: Department of Chemistry, One Shields Ave., University of California, Davis, California 95616, USA.
authors: Jiong
authors: J
authors: Jiang
authors: Marilyn M
authors: MM
authors: Olmstead
authors: Susan M
authors: SM
authors: Kauzlarich
authors: Han-Oh
authors: HO
authors: Lee
authors: Peter
authors: P
authors: Klavins
authors: Zachary
authors: Z
authors: Fisk
mesh_terms: D018360:Crystallography, X-Ray; D005063:Europium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D017553:Phosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012666:Semiconductors; D013499:Surface Properties; D013696:Temperature
chemical_list: D017553:Phosphorus Compounds; D007204:Indium; D005063:Europium