Crystal chemistry and physical properties of the ternary compounds BC (=Ce, Pr, Nd)

Volodymyr Babizhetskyy , Kurt Hiebl , Hansjürgen Mattausch , Arndt Simon

The ternary rare-earth metal boride carbides BC (=Ce, Pr, Nd) were prepared by arc melting the mixtures of the pure elements and subsequent annealing at 1270K. Their crystal structures were determined from single crystal X-ray diffraction data. They crystallize in the CeBC type of structure (space group 2, Z=8). Two new compounds were found, PrBC : =24.592(2) Å, =8.4563(5) Å, =8.4918(5) Å, 1=0.043 (2=0.076) for 2871 reflections with ⩾ 2σ()); for NdBC : =24.301(1) Å, =8.3126(5) Å, =8.3545(4) Å, 1=0.035 (2=0.069) for 3707 reflections with ⩾ 2σ()). Its structural arrangement consists of a three-dimensional framework of rare earth atoms resulting from the stacking of slightly corrugated two-dimensional square nets, leading to voids filled with BC, BC, BC finite chains and isolated carbon atoms. CeBC is an antiferromagnet at 5K followed by a metamagnetic transition in elevated external fields. PrBC and NdBC are ferromagnets below =12K and 15K, respectively.

Mots clés: Rare-earth metal boride carbides; Crystal structure; Magnetism; Resistivity

Volodymyr Babizhetskyy, Kurt Hiebl, Hansjürgen Mattausch, Arndt Simon. Crystal chemistry and physical properties of the ternary compounds BC (=Ce, Pr, Nd). Journal of Physics and Chemistry of Solids, 2009, 70 (3-4), pp.561. ⟨10.1016/j.jpcs.2008.12.011⟩. ⟨hal-00534158⟩