<p>Neodymium-based permanent magnets (Nd2Fe14B) have the potential to be utilised in a wide range of applications owing to their strong magnetic field and resistance to demagnetisation. Due to their exceptional magnetic properties, these magnets have various applications in wind turbines and electric vehicles. Poor mechanical characteristics and low operating temperatures of 585 K are limitations of the Nd₂Fe₁₄B permanent magnet. In this study, we investigate the effect of the rare earth element Terbium (Tb) on the Nd₂Fe₁₄B magnets. Using the ab initio method, the mechanical, magnetic, and structural properties are computed. NdTbFe₁₄B magnet stability is demonstrated by computed elastic characteristics that meet the tetragonal stability restriction. The results suggest that the partial substitution of Nd with Tb improves the stability and operation temperature of Nd₂Fe₁₄B permanent magnets. These findings might potentially guide the development of novel magnetic materials for high-temperature applications.</p> Graphical abstract <p></p>