Growth of thermoelectric Bi/sub 85/Sb/sub 15/ alloy thin films and their characterization by XRD, TEM & RBS

TL;DR: In this paper, the authors used the integral method and the data analyzed by the Jain-Verma theory to evaluate the power index in the energy dependent relaxation time, giving an idea about the nature of scattering.

Abstract: Bismuth and antimony are semimetals. The Bi/sub (1-x)/Sb/sub x/ alloys (0.04

TL;DR: In this paper, the authors focused on the investigation of the transport properties of BiSb alloys and measured electrical resistivity, thermoelectric power and thermal conductivity in a direction perpendicular or parallel to the trigonal axis within the temperature range 4.2 - 300 K on various alloy compositions containing up to 18.2 at.

TL;DR: The electrical resistivity and Hall effect of zone-levelled single crystals of Bi-Sb alloys have been measured in the temperature range from 4.2 to 300 K as discussed by the authors.

Abstract: The electrical resistivity $\ensuremath{\rho}$ and Hall effect $R$ of zone-levelled single crystals of Bi-Sb alloys have been measured in the temperature range from 4.2\ifmmode^\circ\else\textdegree\fi{}K to 300\ifmmode^\circ\else\textdegree\fi{}K. $\mathrm{Log}(\frac{\ensuremath{\rho}}{{\ensuremath{\rho}}_{300}})$ vs $\frac{1}{T}$ curves suggest thermal activation of carriers in the concentration range from 5% to 40% Sb in the temperature range from 25\ifmmode^\circ\else\textdegree\fi{}K to 100\ifmmode^\circ\else\textdegree\fi{}K; approximate activation energies have been inferred from their slopes. The activation energy appears to have a maximum at a concentration near 12%. Some anomalies have been observed in the behavior of $\ensuremath{\rho}$ and $R$ on both sides of this concentration at low temperatures. Lattice parameters for these alloys have also been measured for the entire range of solid solubility. Both a maximum and minimum in the $c$-axis lattice parameter vs concentration occur near the concentration at which anomalies appear in transport properties. These phenomena are discussed in terms of a simple band model proposed by Blount and Cohen.

TL;DR: In this paper, the theoretical expression for the thermoelectric power of polycrystalline metal films is derived from an effective Fuchs-Sondheimer conduction model, and a procedure is proposed to determine the variation in the electronic mean free path.

Abstract: Starting from an effective Fuchs-Sondheimer conduction model, the theoretical expression for the thermoelectric power of polycrystalline metal films is derived. From the approximate expression for thick films, a procedure is proposed to determine the variation in the electronic mean free path.

TL;DR: In this paper, the influence of the milling parameters on the final homogeneity and morphology of the powders, such as ball-to-powder weight ratios (BPR=10:1, 40: 1, 92: 1) and balls sizes (diameters of 30 and 20 mm), was investigated.

Abstract: Polycrystalline Bi 100− x Sb x ( x =7, 10, 12, 15, 22) semiconducting alloys were synthesized by mechanical alloying in order to achieve performant homogeneous thermoelectric materials. The influence of the milling parameters on the final homogeneity and morphology of the powders, such as ball-to-powder weight ratios (BPR=10:1, 40:1, 92:1) and balls sizes (diameters of 30 and 20 mm), was investigated. Powder samples were characterized by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy and electron microprobe analysis. The results show that the samples obtained with the 10:1 BPR and four balls of 30 mm in diameter present the best homogeneity whatever the alloy composition.

TL;DR: In this paper, bismuth-antimony powders containing from 6 to 20 atomic percent of antimony were prepared by evaporation of Bi-Sb pre-alloyed targets using arc energy under argon-hydrogen atmosphere.