Exploring the role of non-stoichiometric in perovskite manganites for magnetocaloric applications: A review

Magnetocaloric effect (MCE) materials possess a unique ability to undergo temperature changes when a magnetic field is applied. These materials are poised to play a pivotal role in advancing sustainable innovations in cooling applications due to their solid-state phase-based approach and their ability to achieve greater energy efficiency compared to conventional vapor-compression refrigeration methods. This review comprehensively provides an overview of the recent advancements and developments in the areas of modified materials, especially in non-stoichiometric perovskite manganite, a topic that has yet to be thoroughly summarized. These materials are essential for summaries since they have a different and unique mechanism from stoichiometric perovskite manganite and need a deeper exploration of the role of non-stoichiometric in perovskite manganite for MCE materials. Additionally, this review comprehensively examines the substantial journey of active magnetic refrigeration technology from its theoretical origins toward technological viability over the past two decades. Our analysis spans historical, fundamental, and applied perspectives, addressing ideal parameters, key experimental results, and the persistent challenges hindering full commercial adoption. Ultimately, this review seeks to provide valuable insights into the modification of MCE materials, particularly through a non-stoichiometric approach, enabling researchers to develop ideal MCE materials for active magnetic refrigeration technology.