Abstract: The double perovskite Ca₂CrSbO₆ exhibits a ferromagnetic long-range order below T _c = 13 K and a saturation magnetization of 2.35 μ _B at 2 K. In this study, the polycrystalline Ca₂CrSbO₆ is synthesized under high pressure and high temperature, and the critical behavior of the ferromagnetic material as well as the effects of the magnetic behavior due to the isovalent substitution of Sr^{2 +} for Ca^{2 +} is investigated. Also studied are the ferromagnetic criticality of the double perovskite Ca₂CrSbO₆ at the ferromagnetic transition temperature T _c ≈ 12.6 K from the isotherms of magnetization M(H) via an iteration process and the Kouvel-Fisher method. The critical exponents associated with the transition are determined as follows: β = 0.322, γ = 1.241, and δ = 4.84. The magnetization data in the vicinity of T _c can be scaled into two universal curves in the plot of $M/\vert \varepsilon \vert ^\beta $ versus $H/\vert \varepsilon \vert ^\beta + \gamma $, where ε =T/T _c-1. The obtained β and γ values are consistent with the predicted values from a three-dimensional Ising model. The effects of Sr substitution on the double perovskite Ca₂CrSbO₆ are taken into consideration. As the Sr content increases, the (Ca_{2 -x}Sr_x)CrSbO₆ polycrystal shows a continuous switch from ferromagnetic to antiferromagnetic behavior.

Key words: high-temperature and high-pressure synthesis, ferromagnet, Ca₂CrSbO₆