Rare-earth compounds, such as Gd-based intermetallics, exhibit strong magnetocaloric effects (MCEs) and emerge as promising candidates for technological applications in magnetic refrigeration and cryogenics. In this work, we conducted a combined experimental and theoretical investigation of the magnetocaloric properties of the orthorhombic ${\mathrm{GdNi}}_4\mathrm{Al}$ crystal. The experimental measurements were performed at ambient pressure, while the effects of hydrostatic pressure up to 20 GPa were investigated theoretically. From $\mathrm{DFT}+U$ and Monte Carlo (MC) simulations, the exchange parameters were determined, and their dependence on pressure was analyzed using different generalized gradient approximations (PBE, PBESol, and AM05). The results show that the exchange interaction between the nearest and next-nearest neighbors are the main factors responsible for the sensitivity of the critical temperature to pressure, while the exchange interaction between next-next-nearest neighbors remains practically unchanged throughout the investigated pressure range. Both mean-field models and MC simulations predict a linear decrease in critical temperature at low pressures, consistent with the Ruderman-Kittel-Kasuya-Yosida coupling mechanism. The MCE, characterized by the maximum entropy variation and the refrigerant capacity, proves to be remarkably stable under compression, remaining practically independent of pressure. Our results demonstrate the structural and magnetic robustness of ${\mathrm{GdNi}}_4\mathrm{Al}$ under extreme conditions and offer a microscopic view of the mechanisms of modulation of pressure-induced MCEs in rare-earth intermetallics.

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• Electronic structure
• Exchange interaction
• Pressure effects
• Crystal structures
• Magnetic refrigeration
• Rare-earth magnetic materials
• Density functional theory
• Monte Carlo methods