Direct measurements of the adiabatic temperature change (ΔTad) in Gd and Mn1.15Fe0.8P0.5Si0.5C0.05 are made using a homemade adiabatic magnetocalorimeter at 260-360 K and 0-7 T. The system uses a servo motor to drive the samples into and out of the magnetic field under a vacuum environment provided by the Physical Property Measurement System (PPMS). The peak values of ΔTad for Gd and Mn1.15Fe0.8P0.5Si0.5C0.05 at 7 T are 8.71 K and 6.41 K at ambient temperatures of 303 K and 317 K, respectively. Based on the theory model, it is found that ΔTad of Gd depends on the 2/3 exponential function of magnetic field H (ΔTad ∝ H2/3), whereas the Mn1.15Fe0.8P0.5Si0.5C0.05 compound follows the power law of ΔTad ∝ H0.66-1.04 due to the first order magnetic transitions. Furthermore, using the constructed experimental instrument, the adiabatic temperature change in different magnetic materials, including materials with first/second order magnetic transition and blocks, flakes, or powders, can be directly measured under large magnetic fields and wide temperature spans.

中文翻译：

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用于直接测量大磁场下磁热效应的简单实用系统

Gd 和 Mn1.15Fe0.8P0.5Si0.5C0.05 的绝热温度变化 (ΔTad) 的直接测量是使用自制的绝热磁热计在 260-360 K 和 0-7 T 下进行的。该系统使用伺服电机驱动在物理特性测量系统 (PPMS) 提供的真空环境下，样品进出磁场。Gd 和 Mn1.15Fe0.8P0.5Si0.5C0.05 在 7 T 时的 ΔTad 峰值在 303 K 和 317 K 的环境温度下分别为 8.71 K 和 6.41 K。根据理论模型，发现Gd的ΔTad取决于磁场H的2/3指数函数（ΔTad ∝ H2/3），而Mn1.15Fe0.8P0.5Si0.5C0.05化合物遵循幂由于一阶磁跃迁，ΔTad ∝ H0.66-1.04 定律。此外，使用构建的实验仪器，