| Examples of Magnetocaloric Materials |
| Paper ID : 1008-ISCHU |
| Authors |
|
Fatema Alzahraa Mohammad *1, Tarek Hammad2, Raghda Abu ElNasr3, Ahmed Abdel Kader2, Sherif Yehia2, Mohammed Said Mohammed Abu-Elmagd4, Samy H Aly5 1Physics department, Faculty of Science, Damietta University. 2Physics Department, Faculty of Science, Helwan University, Cairo, Egypt. 3Damietta university 4Department of Engineering Mathematics and Physics, Higher Institute of Engineering, El Shourok Academy, Cairo, Egypt. 5Physics department, Faculty of Science, Damietta University |
| Abstract |
| We present in this work a summary of our own research on the interesting phenomenon of magnetocaloric effect. The physics of this phenomenon and its applications are of current interest worldwide. The most recognized application is the magnetic cooling. We review our results on several crystalline and amorphous systems , e.g. Er2Fe17, YFe3, HoFe3, R6Fe23, R3Co11B3, Nd2Fe14B, the elements Fe, Co, Ni and the amorphous alloys Gd-Fe and Gd-Co. Our calculation is based on the mean-field theory and on the density-functional theory. We present our results on the temperature and magnetic field dependences of : magnetization, heat capacity, entropy, isothermal entropy change , adiabatic temperature change and relative cooling power. An analysis of the order of the magnetic transitions in these systems is also of interest. Critical exponents of some of the aforementioned systems are calculated and compared with those of the mean-field theory. In addition, high-field investigation on the magnetization curves, at different temperatures, is done to study the possibility of changing the magnetic order, e.g. from ferrimagnetic to ferromagnetic via possible first-order phase transition. |
| Keywords |
| mean field theory, magnetocaloric effect, transition metals, rare earth, magnetic properties |
| Status: Abstract Accepted (Oral Presentation) |