000828001 001__ 828001 000828001 005__ 20210129225950.0 000828001 0247_ $$2doi$$a10.1039/C6RA10189E 000828001 0247_ $$2WOS$$aWOS:000379493900085 000828001 037__ $$aFZJ-2017-02023 000828001 082__ $$a540 000828001 1001_ $$0P:(DE-HGF)0$$aGalivarapu, Jagadish K.$$b0 000828001 245__ $$aEffect of size reduction on cation distribution and magnetic transitions in CoCr$_{2}$ O$_{4}$ multiferroic: EXAFS, magnetic and diffused neutron scattering measurements 000828001 260__ $$aLondon$$bRSC Publishing$$c2016 000828001 3367_ $$2DRIVER$$aarticle 000828001 3367_ $$2DataCite$$aOutput Types/Journal article 000828001 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1488878337_24239 000828001 3367_ $$2BibTeX$$aARTICLE 000828001 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000828001 3367_ $$00$$2EndNote$$aJournal Article 000828001 520__ $$aA rich sequence of magnetic transitions such as para to long-range ferrimagnetic transition at Curie temperature, TC, to a short range non-collinear spiral ordering at spiral ordering temperature, TS, and finally to a lock in transition, TL, are examined in ∼10 and ∼50 nm samples of CoCr2O4 multiferroic through dc, ac magnetic measurements and diffused neutron scattering using polarized neutrons. Analysis of extended X-ray absorption fine structure (EXAFS) spectra and Fourier transforms of Co and Cr edges in real (r) and momentum (k) space show no change in cation distribution among A and B sites even after reducing the size to the nanometer range due to the high crystal field stabilisation energy of Cr3+ towards the B site. While TS remains independent, TC increases from 97.2 to 100.1 K and TL increases from 5 to 8.5 K with varying size from 10 to 50 nm. Temperature dependent ac susceptibility (χ) measurements demonstrate that χ′ and χ′′ do not show any dispersion behaviour in the 10 nm sample. However, we observe splitting of χ′′ into two peaks and one of them shows dispersion behaviour in the 50 nm sample, indicating a core–shell structure. Magnetization vs. magnetic field measurement show hysteresis behaviour with unsaturated magnetization at high magnetic field indicating a ferrimagnetic core surrounded by disordered surface spins. Fitting of χ′′ with an empirical relation Φ = ΔTB/TBΔlog10 ω, and memory effect measurement, further confirm the spin-glass behaviour of the shell in the 50 nm sample. Magnetic ordering temperatures are examined through neutron scattering using a polarized neutron beam, and reveal that while the para- to ferrimagnetic transition, TC, is continuous and long-range in both nanocrystalline particles, TS is found to be sharp, short-range, and commensurate in 50 nm sample 000828001 536__ $$0G:(DE-HGF)POF3-6G15$$a6G15 - FRM II / MLZ (POF3-6G15)$$cPOF3-6G15$$fPOF III$$x0 000828001 536__ $$0G:(DE-HGF)POF3-6G4$$a6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623)$$cPOF3-623$$fPOF III$$x1 000828001 588__ $$aDataset connected to CrossRef 000828001 65027 $$0V:(DE-MLZ)SciArea-120$$2V:(DE-HGF)$$aCondensed Matter Physics$$x0 000828001 65027 $$0V:(DE-MLZ)SciArea-170$$2V:(DE-HGF)$$aMagnetism$$x1 000828001 65017 $$0V:(DE-MLZ)GC-1604-2016$$2V:(DE-HGF)$$aMagnetic Materials$$x0 000828001 693__ $$0EXP:(DE-MLZ)DNS-20140101$$1EXP:(DE-MLZ)FRMII-20140101$$5EXP:(DE-MLZ)DNS-20140101$$6EXP:(DE-MLZ)NL6S-20140101$$aForschungs-Neutronenquelle Heinz Maier-Leibnitz $$eDNS: Diffuse scattering neutron time of flight spectrometer$$fNL6S$$x0 000828001 7001_ $$0P:(DE-HGF)0$$aKumar, D.$$b1 000828001 7001_ $$0P:(DE-HGF)0$$aBanerjee, A.$$b2 000828001 7001_ $$0P:(DE-HGF)0$$aSathe, V.$$b3 000828001 7001_ $$0P:(DE-HGF)0$$aAquilanti, Giuliana$$b4 000828001 7001_ $$0P:(DE-HGF)0$$aRath, Chandana$$b5$$eCorresponding author 000828001 773__ $$0PERI:(DE-600)2623224-8$$a10.1039/C6RA10189E$$gVol. 6, no. 68, p. 63809 - 63819$$n68$$p63809 - 63819$$tRSC Advances$$v6$$x2046-2069$$y2016 000828001 909CO $$ooai:juser.fz-juelich.de:828001$$pVDB$$pVDB:MLZ 000828001 9131_ $$0G:(DE-HGF)POF3-6G15$$1G:(DE-HGF)POF3-6G0$$2G:(DE-HGF)POF3-600$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF3-6G15$$aDE-HGF$$bForschungsbereich Materie$$lGroßgeräte: Materie$$vFRM II / MLZ$$x0 000828001 9131_ $$0G:(DE-HGF)POF3-623$$1G:(DE-HGF)POF3-620$$2G:(DE-HGF)POF3-600$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF3-6G4$$aDE-HGF$$bForschungsbereich Materie$$lVon Materie zu Materialien und Leben$$vFacility topic: Neutrons for Research on Condensed Matter$$x1 000828001 9141_ $$y2017 000828001 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR$$bRSC ADV : 2015 000828001 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS 000828001 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline 000828001 915__ $$0StatID:(DE-HGF)0310$$2StatID$$aDBCoverage$$bNCBI Molecular Biology Database 000828001 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bThomson Reuters Master Journal List 000828001 915__ $$0StatID:(DE-HGF)0111$$2StatID$$aWoS$$bScience Citation Index Expanded 000828001 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection 000828001 915__ $$0StatID:(DE-HGF)1150$$2StatID$$aDBCoverage$$bCurrent Contents - Physical, Chemical and Earth Sciences 000828001 915__ $$0StatID:(DE-HGF)9900$$2StatID$$aIF < 5 000828001 920__ $$lyes 000828001 9201_ $$0I:(DE-Juel1)JCNS-FRM-II-20110218$$kJCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II$$lJCNS-FRM-II$$x0 000828001 9201_ $$0I:(DE-Juel1)JCNS-2-20110106$$kJCNS-2$$lStreumethoden$$x1 000828001 980__ $$ajournal 000828001 980__ $$aVDB 000828001 980__ $$aI:(DE-Juel1)JCNS-FRM-II-20110218 000828001 980__ $$aI:(DE-Juel1)JCNS-2-20110106 000828001 980__ $$aUNRESTRICTED