[Zurück]

B.Ya. Kotur, A.M. Palasyuk, O.R. Myakush, E. Bauer, H. Michor, G. Hilscher:
"Crystal structure and electrical resistivity of the RMn_4.6-xCo_xAl_7.4 and RMn_4.6-xFe_xAl_7.4 (R = Gd, Tb) compounds";
Journal of Alloys and Compounds, 383 (2004), S. 290 - 293.

Crystal structure and electrical resistivity of the RMn4.6−xCoxAl7.4 and RMn4.6−xFexAl7.4 (R = Gd, Tb) compounds

B. Ya. KoturCorresponding Author Contact Information, E-mail The Corresponding Author, a, A. M. Palasyuka, O. R. Myakusha, E. Bauerb, H. Michorb and G. Hilscherb

a Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla and Mefodiya St. 6, UA-79005, Lviv, Ukraine
b Institute of Solid State Physics, TU Wien, Wiedner Hauptstr. 8-10, A-1040, Wien, Austria

Available online 2 June 2004.


Abstract

The RMn4.6−xCoxAl7.4 and RMn4.6−xFexAl7.4 (R = Gd, Tb; x=0.14, 0.46, 2.3) alloys crystallize in the tetragonal ThMn12-type structure (space group I4/mmm). The temperature dependencies of resistivity for these alloys have been studied within the temperature range 4.2-300 K. Hopping conductivity in terms of variable range hopping (VRH) is deduced over a significant temperature range (4.2-60 K) from a behavior of small sigma, Greek(T) according to 1/small rho, Greek=small sigma, Greek(T)=small sigma, Greek0 exp(−A/T1/4). VRH occurs in all RMn4.6−xCoxAl7.4 (x=0.14, 0.46, 2.3) pseudoternary alloys. The increase of Co content in RMn4.6−xCoxAl7.4 alloys leads to an extension of the VRH temperature range. The effect of Fe doping is opposite. The VRH mechanism of transport in RMn4.6−xFexAl7.4 occurs only for small amounts of Fe (x=0.14, 0.46). Large content of Fe (x=2.3) suppresses hopping conductivity in RMn4.6−xFexAl7.4.

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04970153

doi:10.1016/j.jallcom.2004.04.071