Abstract
We observed abnormal magnetic behaviors (so-called inverted hysteresis loops or negative remanence) in a randomly distributed Co nanoparticle (NP) system, where the Co NPs are prepared using laser irradiation. The inverted hysteresis loops are observed when ferromagnetic and superparamagnetic phases coexist within the NP system. Normal hysteresis loops appear in samples having only one phase, either ferromagnetic or superparamagnetic. The ferromagnetic and superparamagnetic Co NPs, with average diameters of 25 and 4 nm, respectively, showed negative remanence over a temperature range of 92--300 K. We have proposed that these abnormal features are directly related to the dipolar interaction between the superparamagnetic Co NPs and a ferromagnetic Co NP.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
