Tuning thermoelectric properties of Ca0.9Gd0.1MnO3 by laser processing

Abstract

Donor-doped CaMnO 3 is an n-type semiconductor with perovskite structure, being considered as a potential n-type leg in thermoelectric modules. This oxide presents stability at high temperatures and allows tuning the relevant electrical and thermal transport properties through doping. In this work, Ca 0.9 Gd 0.1 MnO 3 precursors have been prepared to produce fibres through the laser floating zone technique using different pulling rates. However, as-grown fibres did not present thermoelectric properties due to the presence of high amounts of secondary phases, leading to very high electrical resistivity values. The results have highlighted the importance of annealing procedures to reduce electrical resistivity, due to the decrease of secondary phases amount, and producing promising thermoelectric performances. The annealed samples present higher ZT values when the growth rate is decreased, reaching around 0.22 for the lowest growth rate, which is very close to the best values reported in the literature for these materials. Moreover, this procedure possesses an additional advantage considering that these samples can be directly used as n-type legs in thermoelectric modules for high-temperature applications However, further studies should be made to determine the optimal amount of dopant.

Progress of Laser Processing Technology in Ferroelectric Nanocomposites

“…rough the comparative analysis of the graph neural network cultured on the microfluidic array chip and the graph neural network cultured on the glass slide, the influence of the neural network on the neuron morphology was studied [5]. Ferreira N M prepared MnO 3 precursors to produce fibers by using the laser floating zone technique [6]. Guangyi proposed a novel water-vapor shrinkage-guided high-power laser processing (WSLP) technique.…”

Thermoelectric properties of CaMnO3 ceramics produced by using powder synthesized by modified Pechini method

“…Recent studies of synthesis of CMO-based ceramics reported that different thermoelectrical properties resulted when distinct synthesis methods were adopted and concluded that a chemical route enabled higher ZT values than the statesolid reaction method [15]. Also, the presence of secondary phases affects the electrical conductivity compared to the stoichiometric CMO [16].…”