Synthesis and Ball Milling Effect on Thermal Conductivity of PbTe Based Alloys

Abstract

Lead chalcogenide (PbTe) nanopowders doped with chromium, iodine, silver and lanthanum were obtained by ball-milling ingots grown by the vertical Bridgman technique. These nanopowders were subsequently subjected to consolidating by cold pressing technique and further sintering in a furnace (CPS). In the present work, the effect of ball milling time and second phases on the microstructure and the eventual crystallite size is analyzed. The thermal conductivity versus temperature measurements were conducted and showed decrease in κ values with milling time. The lowest obtained thermal conductivity values were as follows: κ = 0.4W/mK and κ = 0.26W/mK for PbTe:Cr, I and PbTe:Ag,La materials, respectively. Additionally, scanning electron microscopy (SEM) was performed for the samples after different milling time. In order to determine the size of the obtained powder particles the particle size analysis measurements were performed using optical microscopy (Clemex vision software) and X-ray powder diffraction analysis (XRD).

Magnetic Constitution of Topologically Trivial Thermoelectric PbTe:Cr

“…In the latter respect, PbTe has acquired a status of the model example when zT doubled after introduction 1-2% of Tl [6]. Thermoelectric properties of PbTe can be also controlled by incorporation of 3d transition metals, such as Mn, Fe or Cr [7,8,9,10,11,12]. Chromium is particularly interesting since Cr substituting for Pb atoms form a mixed valence Cr 2+/3+ donor centers resonant with the PbTe conduction band [8,13,14,15,16].…”