Dielectric anomalies in monoclinic TlInS2 polytypes

Polytypes in ferroelectric TlInS2 and its dielectric and optic properties

“…g E Δ -values for different Ps are in agreement with deformation potential model [5]. Valuable information about Ps converting was obtained in transparence region ( )…”

Dielectric properties and phase transitions in crystals of TlInS x Se2 − x solid solutions

“…ferences between the PT temperatures in crystals of this family reported by different authors could possibly be attributed to these layered crystals being susceptible to polytypism [10,11]. In TlInS 2 crystals, one observed in some cases pure polytypes with cell parameters c 1 ≈ 15 Å, c 2 ≈ 60 Å, and c 3 ≈ 120 Å, with the temperatures of the PT from the incommensurate to commensurate phase being, respectively, T c1 ≈ 204 K, T c2 ≈ 215 K and T c3 ≈ 201 K. Sometimes a mixture of polytypes can be formed in the crystal; in this case, several anomalies will be observed in the PT region.…”

Spectroscopic Ellipsometry Studies and Temperature Behaviour of the Dielectric Function of TlInS2 Layered Crystal

“…A phenomenological approach applied for the description of the phase transitions in TlInS2 enabled qualitative agreement with the experimental dependence of thermodynamical functions on temperature to be obtained [3][4][5]. For these materials extensive temperature studies of acoustic [6], electrical [7][8][9][10][11][12], and optical [13][14][15][16] properties were carried out while ellipsometric studies of A III B III C VI (A  Tl, B  (In, Ga), C  (S, Se)) chalcogenides were subject of several publications [17][18][19][20][21][22][23][24][25][26].…”