% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Kumar:824840,
      author       = {Kumar, D. and Galivarapu, J. K. and Banerjee, A. and
                      Nemkovskiy, Kirill and Su, Y. and Rath, Chandana},
      title        = {{S}ize-dependent magnetic transitions in
                      {C}o{F}e$_0.1${C}r$_1.9${O}$_4$ nanoparticles studied by
                      magnetic and neutron-polarization analysis},
      journal      = {Nanotechnology},
      volume       = {27},
      number       = {17},
      issn         = {1361-6528},
      address      = {Bristol},
      publisher    = {IOP Publ.},
      reportid     = {FZJ-2016-07342},
      pages        = {175702 1-10},
      year         = {2016},
      abstract     = {Multiferroic, CoCr2O4 bulk material undergoes successive
                      magnetic transitions such as a paramagnetic to collinear and
                      non-collinear ferrimagnetic state at the Curie temperature
                      (T C) and spiral ordering temperature (T S) respectively and
                      finally to a lock-in-transition temperature (T l). In this
                      paper, the rich sequence of magnetic transitions in CoCr2O4
                      after mixing the octahedral site with $10\%$ of iron are
                      investigated by varying the size of the particle from 10 to
                      50 nm. With the increasing size, while the T C increases
                      from 110 to 119 K which is higher than the T C (95 K) of
                      pure CoCr2O4, the T S remains unaffected. In addition, a
                      compensation of magnetization at 34 K and a lock-in
                      transition at 10 K are also monitored in 50 nm particles.
                      Further, we have examined the magnetic-ordering temperatures
                      through neutron scattering using a polarized neutron beam
                      along three orthogonal directions after separating the
                      magnetic scattering from nuclear-coherent and
                      spin-incoherent contributions. While a sharp long-range
                      ferrimagnetic ordering down to 110 K and a short-range
                      spiral ordering down to 50 K are obtained in 50 nm
                      particles, in 10 nm particles, the para to ferrimagnetic
                      transition is found to be continuous and spiral ordering is
                      diffused in nature. Frequency-dependent ac susceptibility
                      (χ) data fitted with different phenomenological models such
                      as the Neel–Arrhenius, Vogel–Fulcher and power law,
                      while ruling out the canonical spin-glass, cluster-glass and
                      interacting superparamagnetism, reveal that both particles
                      show spin-glass behavior with a higher relaxation time in 10
                      nm particles than in 50 nm. The smaller spin flip time in 50
                      nm particles confirms that spin dynamics does not slow down
                      on approaching the glass transition temperature (T g).},
      cin          = {JCNS (München) ; Jülich Centre for Neutron Science JCNS
                      (München) ; JCNS-FRM-II / JCNS-2},
      ddc          = {530},
      cid          = {I:(DE-Juel1)JCNS-FRM-II-20110218 /
                      I:(DE-Juel1)JCNS-2-20110106},
      pnm          = {6G15 - FRM II / MLZ (POF3-6G15) / 6G4 - Jülich Centre for
                      Neutron Research (JCNS) (POF3-623)},
      pid          = {G:(DE-HGF)POF3-6G15 / G:(DE-HGF)POF3-6G4},
      experiment   = {EXP:(DE-MLZ)DNS-20140101},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000372797400017},
      doi          = {10.1088/0957-4484/27/17/175702},
      url          = {https://juser.fz-juelich.de/record/824840},
}