12010-44-5Relevant articles and documents
Electrical transport properties of semimetallic GdX single crystals (X=P, As, Sb, and Bi)
Li,Haga,Shida,Suzuki,Kwon
, p. 10483 - 10491 (1996)
The large single crystals of stoichiometric and nonstoichiometric Gd monopnictides GdX (X=P, As, Sb, and Bi) are grown by the mineralization method (for X=P and As) and Bridgman method (for X=Sb and Bi). A systematic investigation of the transport properties of GdX single crystals is presented. We report on measurements of the electric resistivity p(T), magnetoresistance p(H), and Hall effect performed on the stoichiometric and nonstoichiometric samples at temperatures between 1.6 and 300 K in magnetic fields up to 10 T. The stoichiometric samples behaved as the well-compensated semimetals that order antiferromagnetically at Neel temperatures TN=15.9 K for GdP, 18.7 K for GdAs, 23.4 K for GdSb, and 25.8 K for GdBi. The transverse magnetoresistance measured at low temperature follows a p(//)tx//2 law, and a larger positive ratio MRR =[p(H)- p(0)]/p(0) is observed at 10 T for the four stoichiometric samples. The temperature dependence of the resistivity can be explained by the d-f Coulomb exchange interaction at lower temperatures. The Halleffect measurements yield a carrier concentration ;i=2.1X1020 cm~3 for GdAs and ;i=4.2X1020 cm 3 for , GdSb, which are in a good agreement with the de Haas-van Alphen effect measurements. The nonstoichiometric samples showed some anomalies that could be explained qualitatively by the model of trapped magnetic polaren.
Investigation of the transport properties and compositions of the Ca2RE7Pn5O5 series (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi)
Forbes, Scott,Yuan, Fang,Kosuda, Kosuke,Kolodiazhnyi, Taras,Mozharivskyj, Yurij
, p. 148 - 154 (2016/09/09)
The Ca2RE7Pn5O5 phases (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi) were successfully prepared from high temperature reactions at 1225–1300?°C. These phases maintain the same structure types as the parent RE9Pn5O5 phases, except for a Ca/RE mixing. The study and preparation of these phases was motivated by the desire to shift the metallic type properties of the parent RE9Pn5O5 phases to a level more suitable for thermoelectric applications. Electrical resistivity measurements performed on pure, bulk samples indicated all phases to be narrow band gap semiconductors or semimetals, supporting the charge balanced electron count of the Ca2RE7Pn5O5 composition. Unfortunately, all samples are too electrically resistive for any potential usage as thermoelectrics. Electronic band structure calculations performed on idealized RE9Pn5O5 structures revealed the presence of a pseudogap at the Fermi level, which is consistent with the observed electrical resistivity and Seebeck coefficient behavior.