We have reported the sol-gel synthesis and microstructural, magnetic, magnetocaloric, and critical behaviors of La_0.7Ba_0.15Sr_0.15CoO₃ cobaltite. The XRD data refined by Rietveld technology confirms that a sample has a pure perovskite phase with rhombohedral structure. We tested the magnetization curve near the phase transition temperature (T_C) from ferromagnetic (FM) to paramagnetic (PM), and made the Arrott diagram which confirmed the existence of the secondary phase transition. The obtained magnetic constants from hysteresis loop offer to the sample the possible use in some interesting technological applications. The M(μ₀H, T) isothermal magnetizations have been analyzed to estimate the critical exponents (β, γ, and δ). We found that β exponent is close to that of the mean-field model; however, γ and δ exponents belong to an unconventional model. The reliability of the estimated critical exponents was checked from the magnetic field variations of the magnetic entropy change (− ΔS_m) and the relative cooling power (RCP).

我们已经报道了La _0.7 Ba _0.15 Sr _0.15 CoO ₃钴溶胶的溶胶-凝胶合成以及微观结构，磁性，磁热和临界行为。通过Rietveld技术精炼的XRD数据证实了样品具有带有菱形结构的纯钙钛矿相。我们测试了相转变温度（接近磁化曲线Ť _Ç从铁磁（FM））到顺磁（PM），并取得其确认了第二相转变的存在Arrott图。从磁滞回线获得的磁常数为样品提供了在某些有趣的技术应用中的可能用途。的中号（μ ₀ ħ，T）等温磁化强度进行了分析，以估计临界指数（β，γ和δ）。我们发现，β指数接近于均值场模型。但是，γ和δ指数属于非常规模型。（ -所估计的临界指数的可靠性从磁熵变的磁场的变化检查 ΔS_米），而相对冷却功率（RCP）。