Suppressing Charged Cation Antisites via Se Vapor Annealing Enables p-Type Dopability in AgBiSe -SnSe Thermoelectrics.

Cation disordering is commonly found in multinary cubic compounds, but its effect on electronic properties has been neglected because of difficulties in determining the ordered structure and defect energetics. An absence of rational understanding of the point defects present has led to poor reproducibility and uncontrolled conduction type. AgBiSe is a representative compound that suffers from poor reproducibility of thermoelectric properties, while the origins of its intrinsic n-type conductivity remain speculative.

Hidden Local Symmetry Breaking in Silver Diamondoid Compounds is Root Cause of Ultralow Thermal Conductivity.

Typically, conventional structure transitions occur from a low symmetry state to a higher symmetry state upon warming. In this work, an unexpected local symmetry breaking in the tetragonal diamondoid compound AgGaTe is reported, which, upon warming, evolves continuously from an undistorted ground state to a locally distorted state while retaining average crystallographic symmetry. This is a rare phenomenon previously referred to as emphanisis.

Estimating the lower-limit of fracture toughness from ideal-strength calculations.

Fracture mechanics is a fundamental topic to materials science. Fracture toughness, in particular, is a material property of great technological importance for device design. The relatively low fracture toughness of many semiconductor materials, including electronic and energy materials, handicaps their use in applications involving large external stresses.

Visualizing defect energetics.

Defect energetics impact most thermal, electrical and ionic transport phenomena in crystalline compounds. The key to chemically controlling these properties through defect engineering is understanding the stability of (a) the defect and (b) the compound itself relative to competing phases at other compositions in the system. The stability of a compound is already widely understood in the community using intuitive diagrams of formation enthalpy (ΔH) vs.

Na Doping in PbTe: Solubility, Band Convergence, Phase Boundary Mapping, and Thermoelectric Properties.

Many monumental breakthroughs in -type PbTe thermoelectrics are driven by optimizing a PbNaTe matrix. However, recent works found that > 0.02 in PbNaTe further improves the thermoelectric figure of merit, , despite being above the expected Na solubility limit.