000032454 001__ 32454
000032454 005__ 20210121082902.0
000032454 0247_ $$2doi$$a10.1063/1.4935146
000032454 0248_ $$2sideral$$a92357
000032454 037__ $$aART-2015-92357
000032454 041__ $$aeng
000032454 100__ $$aTorres, T. E.
000032454 245__ $$aValidity of the Néel-Arrhenius model for highly anisotropic CoxFe3-xO4 nanoparticles
000032454 260__ $$c2015
000032454 5060_ $$aAccess copy available to the general public$$fUnrestricted
000032454 5203_ $$aWe report a systematic study on the structural and magnetic properties of CoxFe3_xO4 magnetic nanoparticles with sizes between 5 and 25 nm, prepared by thermal decomposition of Fe(acac)3 and Co(acac)2. The large magneto-crystalline anisotropy of the synthesized particles resulted in high blocking temperatures (42 K < TB < 345 K for 5 < d < 13 nm) and large coercive ¿elds (HC ~ 1600 kA/m for T ¼ 5 K). The smallest particles (hdi¼5 nm) revealed the existence of a mag-netically hard, spin-disordered surface. The thermal dependence of static and dynamic magnetic properties of the whole series of samples could be explained within the Neel–Arrhenius relaxation framework by including the thermal dependence of the magnetocrystalline anisotropy K1(T), without the need of ad-hoc corrections. This approach, using the empirical Br€ukhatov-Kirensky relation, provided K1(0) values very similar to the bulk material from either static or dynamic magnetic measurements, as well as realistic values for the response times (s0 ~ 10^-10s). Deviations from the bulk anisotropy values found for the smallest particles could be qualitativelyconstant explained based on Zener’s relation between K1(T) and M(T).
000032454 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/MAT2010-19326$$9info:eu-repo/grantAgreement/ES/MINECO/MAT2013-42551
000032454 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000032454 590__ $$a2.101$$b2015
000032454 591__ $$aPHYSICS, APPLIED$$b47 / 145 = 0.324$$c2015$$dQ2$$eT1
000032454 592__ $$a0.821$$b2015
000032454 593__ $$aPhysics and Astronomy (miscellaneous)$$c2015$$dQ2
000032454 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000032454 700__ $$aLima Jr., E.
000032454 700__ $$0(orcid)0000-0002-5229-2717$$aMayoral, A.
000032454 700__ $$aIbarra, A.
000032454 700__ $$aMarquina, C.
000032454 700__ $$aIbarra, M. R.
000032454 700__ $$aGoya, G. F.
000032454 773__ $$g118 (2015), 183902 [11 pp]$$pJ. appl. physi.$$tJournal of Applied Physics$$x0021-8979
000032454 8564_ $$s2853481$$uhttps://zaguan.unizar.es/record/32454/files/texto_completo.pdf$$yVersión publicada
000032454 8564_ $$s131062$$uhttps://zaguan.unizar.es/record/32454/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000032454 909CO $$ooai:zaguan.unizar.es:32454$$particulos$$pdriver
000032454 951__ $$a2021-01-21-08:16:20
000032454 980__ $$aARTICLE