caa a22 4500 445380861 CHVBK 20180317143017.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s10948-010-1028-x doi (NATIONALLICENCE)springer-10.1007/s10948-010-1028-x High-Temperature DC-Magnetisation Investigation on Undoped and 5 at.% Cobalt Incorporated TiO2 Nanopowders [Elektronische Daten] [Sudesh Sharma, Sujeet Chaudhary, Subhash Kashyap] Nanocrystalline samples of both undoped TiO2 and with 5 at.% Co at cationic sites were prepared by a simple chemical route. X-ray diffraction study of these samples revealed an increase in lattice parameters due to incorporation of Co in the TiO2 lattice and possibly due to formation of oxygen vacancies. No traces of crystalline Co or any other secondary phases could be detected. High-temperature SQUID measurement of these samples exhibited ferromagnetic signature up to 700K, implying that the Curie temperature of doped and undoped TiO2 exceeds 700K. Vacuum annealing of both types of samples enhanced the ferromagnetic character. The as-prepared and vacuum-annealed Co incorporated TiO2 samples, in addition to the ferromagnetic character, also exhibited a paramagnetic signal. All these measurements strongly support the role of defects in inducing room-temperature ferromagnetism in undoped and Co doped TiO2 nanopowders, which can be explained using the bound magnetic polaron model. Springer Science+Business Media, LLC, 2010 TiO2 nationallicence Room temperature ferromagnetism (RTFM) nationallicence Curie temperature nationallicence Oxygen vacancies nationallicence Doped nanoparticles nationallicence Sharma Sudesh Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut Chaudhary Sujeet Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut Kashyap Subhash Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/1-2(2011-01-01), 839-843 1557-1939 24:1-2<839 2011 24 10948 https://doi.org/10.1007/s10948-010-1028-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10948-010-1028-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sharma Sudesh Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut NATIONALLICENCE 700 1- Chaudhary Sujeet Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut NATIONALLICENCE 700 1- Kashyap Subhash Thin Film laboratory, Department of Physics, Indian Institute of Technology Delhi, 110016, New Delhi, India aut NATIONALLICENCE 773 0- Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/1-2(2011-01-01), 839-843 1557-1939 24:1-2<839 2011 24 10948 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer