08 خرداد 1403
محمود ناصري

محمود ناصری

مرتبه علمی: دانشیار
نشانی:
تحصیلات: دکترای تخصصی / فیزیک-نانو
تلفن: 08132355404
دانشکده: دانشکده علوم پایه

مشخصات پژوهش

عنوان
Effect of calcination temperature on the physical properties of LiFe5O8 nanostructures
نوع پژوهش مقاله چاپ شده
کلیدواژه‌ها
Nanostructures Magnetic materials Raman spectroscopy Optical properties
سال
2019
مجله ADVANCED POWDER TECHNOLOGY
پژوهشگران محمود ناصری

چکیده

The structural properties of LiFe5O8 nanostructures, which were synthesized using a thermal treatment method, were investigated using different characterization methods. The XRD, FESEM and TEM results showed a phase transition from uncompleted a-LiFe5O8 and b-LiFe5O8 phases to completed a-LiFe5O8 phase when the growth calcination temperature shifted from 873 to 973 K. The crystallization was completed at 973 K, revealed by the absence of organic absorption bands in the FT-IR spectra. The results of band gap energy which were studied by UV–vis spectroscopy indicated that when calcination temperature increased, the appraised band gap energy of LiFe5O8 nanostructures decreased. Laser Raman analysis was used to determine the peaks of the synthesized LiFe5O8 nanostructures accurately and to differentiate between the a-LiFe5O8 and b-LiFe5O8 phases around 217 cm1. The results of a vibrating sample magnetometer (VSM) indicated that the magnetic properties differed between these nanostructures so that saturation magnetization and coercivity increased when the calcination temperature increased. The obtained results from electron paramagnetic resonance (EPR) spectroscopy demonstrated that as the growth calcination temperature shifted from 673 to 873 K, the results of g value and DHpp increased up to the maximum value and then reduced for calcined sample at 973 K.