Deepshikha Rathore2025-07-022025-07-022025-06https://doi.org/10.1016/j.jallcom.2025.181292https://gnanaganga.alliance.edu.in/handle/123456789/8299A novel class of magnetism has been discovered as altermagnetism because of opposite spin in real space. Altermagnetism exhibits total net magnetization zero and symmetry-induced spin splitting, which separating it in contrast to both antiferromagnetism and ferromagnetism. This review discusses the theory of altermagnetism including core symmetry mechanism and first principle approaches in theoretical models. Material candidates (e.g. MnTe, Mn₅Si₃, RuO₂, CrSb etc.) and predictions for altermagnetism were demonstrated through criteria for identifying altermagnetic materials, role of machine learning and artificial intelligence (AI) in this discovery, and databases with high-throughput screening efforts. The experimental realization and characterization were discussed via techniques for detecting altermagnetic order (e.g., angle-resolved photoemission spectroscopy (ARPES), neutron scattering, transport), challenges in confirming altermagnetism, and case studies of experimental breakthroughs. A comprehensive functional properties and device applications were described with the help of anomalous Hall effect without net magnetization, spin transport, spin torque, and spin filtering in altermagnets including integration with ferroelectrics, superconductors, and topological materials. A comparison of altermagnetism was illustrated with antiferromagnetism, spin glasses, and topological magnetic phases. The role of computational tools was highlighted by AI-driven materials discovery, inverse design approaches, and data-driven modelling of magnetic behaviour. Some of the significant headwinds were underlined by demonstrating stability and tunability of altermagnetic states, precise detection and control, need for experimental benchmarks, and integration into real-world devices. At the end outlook and future directions were deliberated about, with opportunities for interdisciplinary research, advances in instrumentation and computation, and the roadmap toward altermagnetic-based spintronic platforms.enAltermagnetismSpin splittingZero net magnetizationSpin-momentum lockingBerry curvatureFirst-principles calculationsjournal-article