The Zintl phases AIn₂As₂ (A = Ca, Sr, Ba): new topological insulators and thermoelectric material candidates

Abstract

Recently, there has been a lot of interest in topological insulators (TIs), being electronic materials, which are insulating in their bulk but with the gapless exotic metallic state on their...

Two Polymorphs of BaZn2P2: Crystal Structures, Phase Transition, and Transport Properties

“…With the increasing interest in investigating the electrical and thermal transport properties of several “1–2–2” phases for promising thermoelectric and topological properties, we posit that the α-BaZn 2 P 2 phase holds the potential of being an excellent candidate for exploring these properties because of the magnitude and temperature dependence of S ( T ) at elevated temperatures as well as its cage-like crystal structure. The crystal structure wherein the Ba atom is situated in an oversized cage-like structure formed by Zn and P atoms presents an opportunity for the rattling effect, significantly suppressing the lattice thermal conductivity of this material.…”

Materials design, synthesis, and transport properties of disordered rare-earth Zintl bismuthides with the anti-Th3P4 structure type

“…As such, Zintl phases that combine ions with localized unpaired electrons with excellent thermoelectric properties are likely candidates to explore such exotic states of matter. 2,11,12 This is simply because several emergent thermoelectric materials are also known to host topological properties. 13…”

“…Zintl phases are compounds of metals that are often characterized by their semiconducting behaviors. They present a fertile playground to explore the various electronic and transport properties of materials of interest ranging from the topological phases of matter 1,2 to applications in thermoelectrics 3 and photovoltaics. 4,5 Leveraging on the idea of the Zintl-Klemm concept 6 allows for a myriad of opportunities to conceptualize, design, and grow new materials at the heart of cutting-edge technological applications.…”

“…Structural complexity that has to do with intricate chemical bonding is another hallmark of the Zintl phases; this can give rise to glass-like thermal conductivity and high electrical conductivity driven by their narrow bandgap. 2,3,7 As such, materials that combine these features with a significantly high Seebeck coefficient are of interest in achieving an enhanced thermoelectric figure of merit zT = α 2 σ/(κ e + κ l ) at a given operating temperature T. Here, α, σ, κ e and κ l are the Seebeck coefficient, electrical conductivity, electronic thermal conductivity, and lattice thermal conductivity, respectively. 7 The incorporation of magnetic species into a crystal structure that leads to an intrinsic magnetic phase transition as well as the manifestation of the heavy-fermion state [8][9][10] are now being explored as new routes for enhanced thermoelectric performance.…”

“…For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/d2dt00412g properties are likely candidates to explore such exotic states of matter. 2,11,12 This is simply because several emergent thermoelectric materials are also known to host topological properties. 13 Substitution studies aimed to achieve a balanced electron count and with an attendant crystallographic disorder are fueled by the desire to achieve an optimal performing thermoelectric generator.…”