Crystal Growth and some Properties of Tm(Al1-xMox)B4 Synthesized by Al-Flux

Abstract

Crystals of the solid solution Tm(Al1-xMox)B4(x = 0.002 - 0.050) were grown from Tm2O3, metal Mo and crystalline boron powders as starting materials under an Ar atmosphere at 1773 K for 5 h. Tm(Al1-xMox)B4crystals were obtained as a single phase in the case of Al1-xMoxflux (x = 0.005 and 0.010). Tm(Al1-xMox)B4crystals at a maximum size of about 2.2 mm were obtained in the shape of a flake, and together with needle-like crystals of MoAlB and an unknown phase using Al0.970Mo0.030flux. The lattice constants of Tm(Al1-xMox)B4(x = 0.005 - 0.010) crystals were determined to be larger compared to those obtained for TmAlB4. This is related to the fact that the ionic radius of Mo is larger than the ionic radius of Al. When the Al position in the TmAlB4structure was substituted with Mo having a large ionic radius, the hardness hardly changed. In contrast to TmAlB4, no antiferromagnetic transition could be observed for Tm(Al0.995Mo0.005)B4, indicating that the disorder introduced by Mo-doping disrupted the magnetic transition.