Effects of partial anion substitution on the thermoelectric properties of silver(I) chalcogenide halides in the system Ag5Q2X with Q=Te, Se and S and X=Br and Cl

Low-temperature structure and lattice dynamics of the thermoelectric clathrate Sn24P19.3I8

“…This problem is tackled in different ways. The proposed solutions include various kinds of nanostructuring [4,5], building materials from heavy elements [6], introducing a severe disorder into the crystal structure of a material [7,8], and employing the localized vibrations of atoms trapped inside the oversized cages. For the latter solution, two types of cage compounds are commonly used: filled skutterudites [9] and clathrates [10].…”

The Influence of d10-d10 Interactions in Ag5Te1.8Se0.2Cl and Ag5Te1.6Se0.4Cl on Structural and Thermoelectric Properties

“…2 the silver distribution is denoted [12] and characterized by powder phase X-ray analyses and EDX measurements [13]. Phase-pure samples were used to verify the polymorphism of these compounds; effects observed in the differential scanning calorimetry measurements (DSC) are equal to the literature values [15] and lie at the onset temperatures of 273(1) and 303(1) K, respectively [12]. The endothermic effect representing the β -α phase transition is shifted to a lower temperature compared with the ternary phase.…”

“…A modulation of the electronic structure can be achieved based on these low-dimensional interactions which do significantly influence the thermopower and the thermal diffusivity of these materials [12,18]. A strong influence on the electronic structure and the thermopower originating from a Peierls-distorted situation has also been postulated for lead chalcogenides (PbQ with Q = S, Se, Te) under high-pressure conditions [19].…”

“…Significant variations of the thermoelectric properties like thermopower, thermal diffusivity and the thermoelectric figure of merit can be assigned to such oriented, low-dimensional interactions around the silver order/disorder phase transition [11,12].…”

Unexpected Role of Metal Halides in a Chalcogenide Glass Network

“…The main goal of the present contribution is to unravel a previously unknown structural role of silver halides in pseudo-binary AgY-As 2 S 3 glasses belonging to the critical percolation domain, (AgI) 0.1 (As 2 S 3 ) 0.9 (y = 2.13 at.% Ag), and modifier-controlled region, (AgBr) 0.5 (As 2 S 3 ) 0.5 (y = 14.29 at.% Ag), using Raman spectroscopy, diffraction techniques and FPMD. The latter alloy also seems to be a promising precursor for thermoelectric applications [17][18][19], starting from the first patent to recently calculated super-high thermoelectric figure of merit ZT % 7 for similar metal halides and chalcogenides. A deep insight into the structure will be crucial for improving design of new thermoelectric amorphous materials, including printed thermoelectric sheets [20], as well as phasechange memories [21,22], materials for energy storage [23,24], photodetection [25] and spintronics [26].…”