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Modern technology for refrigerators and coolers is based on the chemical gas Chlorofluorocarbon (CFC) compression method that is indicative of a high consumption of electricity. The CFC is also understood as a reason for global warming. One of the solutions to this issue is magnetic refrigeration technology, which is environmentally friendly because it does not use any hazardous chemicals or ozone depleting/greenhouse gases. Magnetic refrigeration technology is based on the magnetocaloric effect of magnetic refrigerant materials. Exploring the magnetocaloric effect of magnetic refrigerant materials is important because these contain many of the physical properties needed for magnetic refrigeration technology.

Manganite perovskite withA-site deficiency has been synthesized by a solid-state reaction technique. Our work does not support a general view that A-site deficiency gives a decrease on Curie temperature. The Curie temperature of (La 0.8 Ca 0.2 ) 0.975 MnO 3.01 is 188 K with maximum entropy change − S M max = 1.6 J•kg −1 •K −1 and refrigerant capacity (RC) of 27 J/kg under an applied field of 10 kOe. The nonstoichiometric (La 0.8 Ca 0.2 ) 0.975 MnO 3.01 may offer a wider temperature span of ∼240% compared with those nanocrystalline La 0.8 Ca 0.2 MnO 3.01 that have similar RC, which has been reported by others.