Universality of weak ferromagnetism in the magnetically frustrated system R 1−x Y x B 4

Emergence of anomalous weak ferromagnetism in geometrically frustrated magnetic system of R 1− x Y x B 4 ( R = Tb and Dy) is quite interesting [Phys. Rev. B 91 , 024414 (2015)]. In order to study the weak ferromagnetism in other compounds, the magnetic properties of R 1− x Y x B 4 ( R = Sm, Gd, and Er) were investigated. The anomalous weak ferromagnetism was also found to occur in all compounds, R 1− x Y x B 4 ( R = Sm, Gd, and Er). The weak ferromagnetism is revealed in the magnetic easy plane, (001), for R 1− x Y x B 4 ( R = Sm and Gd) and along the magnetic easy axis, [001], for R 1− x Y x B 4 ( R = Er). The magnitude of saturated magnetic moment at T = 2 K shows a strong dependence on Y-concentration, i.e., the maximum magnitude occurs at x ≈ 0.3 for all compounds. The general magnetic properties of weak ferromagnetism is quite similar to the weak ferromagnetism in R 1− x Y x B 4 ( R = Tb, Dy). Therefore, it is experimentally demonstrated that the emergence of weak ferromagnetism, induced by non-magnetic substitution in a magnetically frustrated system, is the universal feature in R B 4 compounds.