Magnetocaloric Effect for NaFeO 2 Nanoparticles
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ORIGINAL PAPER
Magnetocaloric Effect for NaFeO2 Nanoparticles Mahmoud A. Hamad 1
&
O. M. Hemeda 2 & Hatem R. Alamri 3 & Ashraf M. Mohamed 4
Received: 4 July 2020 / Accepted: 8 August 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The magnetocaloric effect (MCE) of NaFeO2 nanoparticles has been investigated by phenomenological model (PM). The simulated temperature-dependent magnetization data are in good agreement with the experimental one. Based on PM, the MCE parameters obtained as results of simulation for temperature-dependent magnetization data. Furthermore, the simulation shows that NaFeO2 nanoparticles have a prospective importance in magnetic refrigerants over a wide temperature range, including room temperature. This gives NaFeO2 nanoparticles potentially practical for MR. Keywords Magnetocaloric effect . NaFeO2 nanoparticles . Magnetic entropy change
1 Introduction The solid materials whose magnetocaloric effect (MCE) have been studied extensively over the last 30 years [1–6]. Magnetic refrigerator (MR) deliberately depends on MCE to be more efficient in the cooling process with minimizing the negative impact of the environment over traditional refrigerators [3, 7–13]. The MCE is described as a phenomenon associated with a change in the entropy induced by magnetic field change [14–17]. In MCE, the direction of magnetic spins in magnetic atoms turns to parallel to the direction of an applied magnetic field, causing a decrease in magnetic entropy change (ΔSM) [18–20]. To compensate this decrease of ΔSM, the temperature of the material rises. However, these magnetic spins are randomized when the applied magnetic field is decreased or removed, causing a reduction in the temperature of this * Mahmoud A. Hamad [email protected] Hatem R. Alamri [email protected] 1
Basic Science Department, Higher Institute of Engineering & Technology, King Marriott Academy, Alexandria, Egypt
2
Physics Department, Faculty of Science, Tanta University, Tanta, Egypt
3
Physics Department, Aljamoum University College, Umm Al-Qura University, Makkah 21955, Saudi Arabia
4
Applied Organic Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt
magnetic material [19–21]. In this context, there is a tendency in the use of manganite, alloys, and other magnetic materials for use in MR technology [9, 22–27]. On the other hand, there is an increased interest in the discovery of new materials in the size of nanostructures to obtain distinctive characteristics used in many applications [28]. One of these materials is NaFeO2 belongs to delafossite compounds which takes ABO2 structure (A is monovalent atom, B is trivalent atom) [29]. NaFeO2 has three forms of structure, namely α-NaFeO2 which is present in low temperature, β-NaFeO2 which is present in the medium temperature, and γ-NaFeO2 which is present in the high temperature [30]. Singh et al. have studied and prepared 37 nm NaFeO2 by sol-gel method, showing that these nanoparticles have direct band gap 2.35 eV, superparamagn
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