Table-like magnetocaloric effect involving the enhancement of refrigerant capacity in (AMn_0.9Ti_0.1O₃)_1−x/(AMn_0.85Ti_0.15O₃)_x composite

ABSTRACT

In this paper, a table-like magnetocaloric effect (MCE) is obtained in the (AMn_0.9Ti_0.1O₃)_1−x/(AMn_0.85Ti_0.15O₃)_x composite system. A flattening behaviour of the entropy change is investigated from the isothermal magnetic entropy change versus temperature curves ∆S(T) of AMn_0.9Ti_0.1O₃ and AMn_0.85Ti_0.15O₃ (A = La_0.57Nd_0.1Pb_0.33) manganite materials. Both compounds exhibit nearly some large MCE, 5.2–4.85 J kg⁻¹ K⁻¹, under an applied field of 0–5 T, around their respective Curie temperature (T_C) ranged from 279 to 299 K. The temperature dependence of the isothermal magnetic entropy change ΔS(T) is calculated for (AMn_0.9Ti_0.1O₃)_1−x/(AMn_0.85Ti_0.15O₃)_x composite with 0 ≤ x ≤ 1. The optimum ΔS(T) of the composite with x = 0.495 approaches a nearly constant value of ∼3.63 J kg⁻¹ K⁻¹ in a field change of 0–5 T in a wide temperature span over 15 K, resulting in large refrigerant capacity value of ∼172.3 J kg⁻¹. The (AMn_0.9Ti_0.1O₃)_0.505/(AMn_0.85Ti_0.15O₃)_0.495 composite system indicates that this approach can be used to design magnetic refrigerant materials with enhanced magnetocaloric response in a magnetic refrigerator performing an Ericsson cycle near room temperature.

KEYWORDS:

• Manganite
• composite
• magnetization
• magnetocaloric effect
• table-like

Acknowledgments

The author acknowledges support from Tunisian Ministry of Higher Education and Scientific Research.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

This study is supported by the Tunisian Ministry of Higher Education and Scientific Research.