Magnetocaloric effect in the vicinity of second order antiferromagnetic transition of Er2Mn2O7 compound at different applied magnetic field

• Published in: Journal of alloys and compounds Vol. 563; pp. 28 - 32
• Main Authors: Ben Amor, N., Bejar, M., Dhahri, E., Valente, M.A., Garden, J.L., Hlil, E.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.06.2013; Elsevier
• Subjects: Alloys; Arrott plots; Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Curie temperature; Domain effects, magnetization curves, and hysteresis; Entropy; Exact sciences and technology; Exchange and superexchange interactions; Extrapolation; Low temperature; Magnetic fields; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Magnetocaloric effect; Magnetocaloric effect, magnetic cooling; Materials Science; Néel temperature; Physics; Refrigeration; Saturation; Néel temperature; Magnetocaloric effect; Arrott plots; Low temperature; Antiferromagnetism; Temperature dependence; Second order; Landau theory; Curie point; Magnetization; Curie-Weiss law; Magnetic field effects; Magnetic moments; Very low temperature; Arrott plot; Magnetic refrigerators; Magnetocaloric effects; Neel temperature; Exchange interactions
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.02.008

► Presence of antiferromagnetic exchange and magnetic transition at the Néel temperature. ► The Landau theory is the best model describing the critical properties. ► The Curie Weiss temperature (θCW)M is determined from the magnetization measurements. ► The (θCW)L value is also deduced from the Landau model at low magnetic field. ► Good agreement between the (θCW)M and (θCW)L values. Magnetic studies on Er2Mn2O7 compound are reported. The Curie Weiss temperature has been analyzed by a linear extrapolation of the temperature dependence of the magnetization M(T) curves and the Landau model. The applied magnetic field (μ0H) dependence of the magnetization has revealed the absence of any saturation. This behavior has been explained by the fact that both Er3+ and Mn4+ elements carry magnetic moments, leading to a competition between the magnetic interactions at low temperatures. Close to the Néel temperature, a large change in the magnetic entropy has been observed, which suggests that our Er2Mn2O7 compound can be considered as potential candidate for magnetic refrigeration application at very low temperature.