Trends in thermodynamic parameters of phase transitions of lanthanide sulfides SrLnCuS3 (Ln = La–Lu)

Synthesis, structure, and properties of EuErCuS3

“…3). Similar transitions were detected in ALnCuS 3 (A = Sr or Eu) isostructural compounds [7,17]. The polymorphs of the compound are denoted in the increasing order of temperatures as and EuErCuS 3 .…”

“…Structural types (STs) of EuLnCuS 3 (Ln = La-Lu) compounds determined in samples annealed at 1170 K. The ALnCuS 3 (A = Sr, Eu; Ln = Gd, Dy, and Ho) compounds experience three polymorphic transitions at temperatures above 1400 K upon heating and cooling as shown by differential scanning calorimetry (DSC) [7,17,18]. For EuHoCuS 3 , the polymorphic transition temperatures and enthalpies are T α↔β = 1516 K, ΔH α↔β =3.7 kJ/mol; T β↔γ =1562 K, ΔH β↔γ =1.2 kJ/mol; and T γ↔δ = 1591 K, ΔH γ↔δ = 2.2 kJ/mol [17].…”

“…High-temperature polymorphs have not been obtained by cooling or quenching. The EuLnCuS 3 compounds melt incongruently: EuLaCuS 3 (1539±4 K), EuCeCuS 3 (1524±3 K), EuPrCuS 3 (1497±3 K), EuNdCuS 3 (1470±4K) [8,16]), EuGdCuS 3 (1720±5 K) [7], EuHoCuS 3 (1721±5 K) [17] and EuDyCuS 3 (1721±4K) [18].…”

“…iii -Eu-S3 ix S1 iv -Er-S1 x 71.83 (11) 139.01 (7) 74.83 (11) 79.39 (11) 74.13 (11) 122.99 (12) 89.37(9) 146.64 (13) 79.63 (12) 82.7(1) 136.17 (13) 82.98 (10) 91.24 14S1 iv -Er-S2 v S1 iv -Er-S2 xi S1 iv -Er-S3 S1 iv -Er-…”

“…Complex rare-earth chalcogenides АLnCuS 3 (А 2+ = Pb, Eu, Sr, or Ba) have specific electric [1][2][3][4][5][6], thermal [7][8][9][10][11], magnetic [1,[12][13][14], and optical [1,8,11,14] properties. X-ray powder diffraction experiments on samples annealed at 1170 K showed three types of orthorhombic crystal structures to exist in the EuLnCuS 3 (Ln = La-Ho, Tm-Lu) series [12,15,16] ( Table 1).…”