Electrical Transport Properties of Ga(As_xSb_1−x) and (Ga_xIn_1−x)Sb Alloys under Hydrostatic Pressure

Abstract

Del1ortt,7errt, Ut~i~jo.si?y of'0ttn11~ci. O t t t r u~~, Cotzodo Homogeneous polycrystalline n type samples of the alloys Ga (As,Sb, -, ) and (Ga,In, -,)Sb have been prepared from a stoichiometric melt by directional freezing methods. Room temperature measurements of electrical conductivity and Hall coefficient as a function of hydrostatic pressure up to 12 kbars have been made on samples of different composition by means of the van der Pauw technique, all specimens used in the measurements being carefully selected to avoid the presence of grain boundary effects. The experimental curves of conductivity and Hall coefficient as a function of pressure have been fitted to a two conduction band model with various band parameters taken as adjustable. The curves thus fitted give consistent values of El,, the energy separation of the two bands, as a function of x . For (Ga,ln,-,)Sb, the El, values are in good agreement with those obtained previously from measurements as a function of temperature, no previous values having been published for Ga (As,Sbl-,). Approximate values for the coupling coefficient Dl, of the alloys are also obtained.On a prepare a partir d'un melange stoichiometrique fondu, par des mkthodes de solidification directionnelle, des Cchantillons de type n, homogenes et polycristallins, d'alliages Ga(As,Sb,-,) et (Ga,In, -,)Sb. Des mesures a temperature ambiante de la conductivitk Clectrique et du coefficient de I'effet Hall, en fonction de la pression jusqu'a 12 kbars, ont CtC effectuees sur des echantillons de differentes compositions, au moyen de la technique de van der Pauw, les specimens utilises Ctant choisis avec soin pour tviter la presence d'effets de frontieres de grains. Les courbes experimentales de conductivitt et d'effet Hall ont permis de donner des valeurs aux parametres ajustables d'un modele a deux bandes de conduction. Cet ajustement a permis d'obtenir des valeurs coherentes pour El,, la difference d'knergie entre les deux bandes, en fonction de x. Pour (Ga,ln,-,)Sb, les valeurs de El, sont en bon accord avec celles qui ont ete obtenues anterieurement a partir de mesures en fonction de la temperature; pour Ga(As,Sbl -, ) il n'existe pas de valeurs publiees. On a aussi obtenu des valeurs approximatives de Dl,, le coefficient de couplage des alliages.[Traduit par le journal]Can. J. Phys.. S3,1071 (1975)

Electron effective mass values in GaAsxSb1−x alloys

“…lattice parameter a, with composition x being known In previous work (3), samples of these alloys were (4). produced by slow horizontal Bridgman growth.…”