In this paper, we present a thorough study for the critical behavior of AMn_1-xTi_xO₃ (A = La_0.5Pr_0.2Sr_0.3, x = 0.0 and 0.2) polycrystalline samples by analysing their isothermal magnetization data using various technique such us modified Arrott plots, Kouvel-Fischer method, and critical magnetisation isotherms M(T_C,H). The critical exponent values for the undoped compound allowed us to assign a mean field universality class with long-range interactions (β = 0.509,γ = 1.094,δ = 3.14). The non-magnetic Ti-substitution does not affect the class of universality. The analysis shows that the critical exponents of all compounds were close to those of the mean field model with long-range interaction. The field dependence of the magnetic entropy change is also analyzed using-\(\Delta S_{M} = a\left( H \right)^{n}\) power law, where the exponent n values ranging between 0.68 and 0.74 are close to those obtained from the theoretical relation \(n(T_C) = 1 + \left(\left( \beta - 1\right)/\left(\beta + \gamma \right)\right)\). The second-order nature of the magnetic phase transition has been confirmed by constructing the universal magnetic entropy change curves. The spontaneous magnetization values determined using the magnetic entropy change (∆S_M vs. M²) are in good agreement with those obtained from the classical extrapolation of Arrott curves (H/M vs. M²).

在本文中，我们 通过使用各种技术分析等温磁化数据，对AMn _1-x Ti _x O ₃（A = La _0.5 Pr _0.2 Sr _0.3，x = 0.0和0.2）多晶样品的临界行为进行了深入研究。我们修改了 Arrott 图、Kouvel-Fischer 方法和临界磁化等温线 M(T _C ,H)。未掺杂化合物的临界指数值使我们能够分配具有长程相互作用的平均场普遍性类别 ( β  = 0.509, γ  = 1.094, δ = 3.14）。非磁性 Ti 取代不影响通用性等级。分析表明，所有化合物的临界指数都接近具有长程相互作用的平均场模型的临界指数。还使用- \(\Delta S_{M} = a\left( H \right)^{n}\)幂律分析了磁熵变化的场依赖性，其中指数n值介于 0.68 和 0.74 之间是接近从理论关系获得的那些\(n(T_C) = 1 + \left(\left( \beta - 1\right)/\left(\beta + \gamma \right)\right)\). 磁相变的二阶性质已通过构建通用磁熵变曲线得到证实。使用磁熵变（ΔS _M对 M ²）确定的自发磁化值与从阿罗特曲线的经典外推法（H/M 对 M ²）获得的值非常一致。