High pressure synthesis of LnCrS3 (Ln = La, Ce, Nd, Sm) and LaCr1−xFexS3 (x ≤ 0.2) with NH4CdCl3 structure type

LnCrS3 (Ln = La, Ce, Nd, Sm) with NH4CdCl3 structure type were prepared in high pressure synthesis at 4 GPa, 1373 K for 2 h. Their orthorhombic lattice parameters were a = 0.787(2), b = 0.385(1), c = 1.334(3) nm for LaCrS3; a = 0.776(4), b = 0.379(2), c = 1.316(7) nm for CeCrS3; a = 0.769(2), b = 0.377(1), c = 1.306(4) nm for NdCrS3; and a = 0.764(5), b = 0.374(2), c = 1.297(8) nm for SmCrS3. The Ln3+ ions are coordinated with nine S2− ions in CrS6 double chains. The products are antiferromagnetic semiconductors. The paramagnetic temperature Θ varied with a Cr–Cr distance in the CrS6 double chain. They also showed a weak ferromagnetic behavior at low temperature below 120 K. Magnetic hysteresis was observed for the ferromagnetism between ZFC and FC measurements. LaCr1−xFexS3 solid solution with NH4CdCl3 structure type was also obtained in high pressure synthesis at 4 GPa, 1473 K for 2 h. The Fe3+ in high spin state substitutes the Cr3+ up to about x = 0.2.