TY - JOUR
T1 - Magnetic properties and negative colossal magnetoresistance of the rare earth Zintl phase EuIn2As2
AU - Goforth, Andrea M.
AU - Klavins, Peter
AU - Fettinger, James C.
AU - Kauzlarich, Susan M.
PY - 2008/12/1
Y1 - 2008/12/1
N2 - Large, high quality single crystals of a new Zintl phase, EuIn 2As2, have been synthesized from a reactive indium flux. EuIn2As2 is isostructural to the recently reported phase EuIn2P2, and it is only the second reported member of the group of compounds with formula AM2X2 (A = alkali, alkaline earth, or rare earth cation; M = transition or post-transition metal; and X = Group 14 or 15 element) that crystallizes in the hexagonal space group P63/mmc (a = 4.2067(3) Å, c = 17.889(2) Å and Z = 2). The structure type contains layers of A2+ cations separated by [M 2X2]2- layers along the crystallographic c-axis. Crystals of the title compound were mounted for magnetic measurements, with the crystallographic c-axis oriented either parallel or perpendicular to the direction of the applied field. The collective magnetization versus temperature and field data indicate two magnetic exchange interactions near 16 K, one involving Eu2+⋯Eu2+ intralayer coupling and the other involving Eu2+⋯Eu2+ coupling between layers. EuIn2As2 is metallic and magnetoresistive, as is the isostructural phosphide, and both compounds have coincident resistivity and magnetic ordering transitions, consistent with the observation of colossal magnetoresistance. Negative colossal magnetoresistance (MR = {[p(H) - p(0)]/ρ(H)} x 100%) of up to -143% (at T = 17.5 K, H = 5 T) is observed for EuIn2As2, approximately half of that observed for the more resistive phosphide, which has a higher magnetic ordering temperature and local moment coupling strength.
AB - Large, high quality single crystals of a new Zintl phase, EuIn 2As2, have been synthesized from a reactive indium flux. EuIn2As2 is isostructural to the recently reported phase EuIn2P2, and it is only the second reported member of the group of compounds with formula AM2X2 (A = alkali, alkaline earth, or rare earth cation; M = transition or post-transition metal; and X = Group 14 or 15 element) that crystallizes in the hexagonal space group P63/mmc (a = 4.2067(3) Å, c = 17.889(2) Å and Z = 2). The structure type contains layers of A2+ cations separated by [M 2X2]2- layers along the crystallographic c-axis. Crystals of the title compound were mounted for magnetic measurements, with the crystallographic c-axis oriented either parallel or perpendicular to the direction of the applied field. The collective magnetization versus temperature and field data indicate two magnetic exchange interactions near 16 K, one involving Eu2+⋯Eu2+ intralayer coupling and the other involving Eu2+⋯Eu2+ coupling between layers. EuIn2As2 is metallic and magnetoresistive, as is the isostructural phosphide, and both compounds have coincident resistivity and magnetic ordering transitions, consistent with the observation of colossal magnetoresistance. Negative colossal magnetoresistance (MR = {[p(H) - p(0)]/ρ(H)} x 100%) of up to -143% (at T = 17.5 K, H = 5 T) is observed for EuIn2As2, approximately half of that observed for the more resistive phosphide, which has a higher magnetic ordering temperature and local moment coupling strength.
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U2 - 10.1021/ic801290u
DO - 10.1021/ic801290u
M3 - Article
C2 - 18959371
AN - SCOPUS:57949100103
VL - 47
SP - 11048
EP - 11056
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 23
ER -