[16p-Z35-1~8] 9.5 New functional materials and new phenomena

[16p-Z35-5] Colossal barocaloric effects in charge transfer oxides

Yoshihisa Kosugi¹, Masato Goto¹, Asaya Fujita², Takashi Saito³, Takashi Kamiyama³, Daisuke Kan¹, 〇Yuichi Shimakawa¹ (1.ICR, Kyoto Univ., 2.AIST Cyubu, 3.KEK)

Keywords:caloric effect, transition-metal oxides, charge transition

In this study, we discovered a novel charge transfer oxide, NdCu₃Fe₄O₁₂, that shows the colossal latent heat of 25.5 kJ/kg, which corresponds to a large entropy change of 84.2 J/ kg K, driven by an unusual first-order intersite-charge-transfer transition occurring near room temperature. Importantly, we demonstrated that the large latent heat is utilized through the barocaloric effect. The observed entropy change by the barocaloric effect is much larger than those reported in known giant barocaloric materials and is comparable to the largest values reported in inorganic solid materials.