The magnetic entropy change in the double perovskite La2NiMnO6 with strong spin–phonon coupling

The magnetocaloric effect and the critical behavior of La2NiMnO6 are investigated by measurement of the magnetization around TCTC. The magnetic entropy change |ΔS||ΔS| of La2NiMnO6 for a field change of 0–45 kOe near the Curie temperature is about 5% of the theoretical expectation. The critical behavior of the La2NiMnO6 deviates from the mean field theory. These abnormal phenomena are understood in the context of the strong spin–phonon coupling in La2NiMnO6. It is suggested that a method of modulating this coupling would enhance the magnetic entropy change greatly, which makes the La2NiMnO6 a promising candidate for room-temperature magnetic refrigeration.