caa a22 4500 445828528 CHVBK 20180317145306.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10854-010-0265-x doi (NATIONALLICENCE)springer-10.1007/s10854-010-0265-x Reaction kinetic, magnetic and microwave absorption studies of SrFe11.2Ni 0.8O19 hexaferrite nanoparticles [Elektronische Daten] [Sachin Tyagi, Ramesh Agarwala, Vijaya Agarwala] Nickel substituted strontium hexaferrite, SrFe11.2Ni 0.8O19 nanoparticles having super paramagnetic nature were synthesised by co-precipitation of chloride salts using 7.5M sodium hydroxide solution. The resulting precursors were heat treated (HT) at 900 and 1,200°C for 4h in nitrogen atmosphere. During heat treatment, transformation proceeds as a constant rate of nucleation and three dimensional growth with activation energy of 183.724kJ/mole. The hysteresis loops showed an increase in saturation magnetization from 1.045 to 65.188emu/g with increasing HT temperatures. The ‘as-synthesised' particles have size in the range of 20-25nm with spherical and needle shapes. Further, these spherical and needle shaped nanoparticles tend to change their morphology to hexagonal plates with increase in HT temperatures. The effect of such a systematic morphological transformation of nanoparticles on dielectric (complex permitivity and permeability) and microwave absorption properties were estimated in X band (8.2-12.2GHz). The maximum reflection loss of the composite powder reaches −24.92dB at the thickness of 2.2mm which suits its application in RADAR absorbing materials. Springer Science+Business Media, LLC, 2010 Tyagi Sachin Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut Agarwala Ramesh Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut Agarwala Vijaya Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut Journal of Materials Science: Materials in Electronics Springer US; http://www.springer-ny.com 22/8(2011-08-01), 1085-1094 0957-4522 22:8<1085 2011 22 10854 https://doi.org/10.1007/s10854-010-0265-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10854-010-0265-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tyagi Sachin Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut NATIONALLICENCE 700 1- Agarwala Ramesh Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut NATIONALLICENCE 700 1- Agarwala Vijaya Surface Engineering Lab, Metallurgical and Materials Engineering Department, Indian Institute of Technology, 247667, Roorkee, India aut NATIONALLICENCE 773 0- Journal of Materials Science: Materials in Electronics Springer US; http://www.springer-ny.com 22/8(2011-08-01), 1085-1094 0957-4522 22:8<1085 2011 22 10854 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer