TY  - JOUR
AU  - Kumar, Durgesh
AU  - Nemkovskiy, Kirill
AU  - Su, Y.
AU  - Rath, Chandana
TI  - Enhancement of Curie- and spin-spiral temperatures with doping Fe in multiferroic CoCr2O4 nanoparticles
JO  - Journal of magnetism and magnetic materials
VL  - 488
SN  - 0304-8853
CY  - Amsterdam
PB  - North-Holland Publ. Co.
M1  - FZJ-2019-03309
SP  - 165378 -
PY  - 2019
AB  - Multiferroic, CoCr2O4 bulk material undergoes successive magnetic transitions such as paramagnetic to collinear ferrimagnetic state at Curie temperature (TC) and non-collinear spin-spiral ordering temperature TS followed by a lock-in-transition TL. In this paper, the rich sequence of magnetic transitions in CoCr2O4 nanoparticles after doping with iron ions are investigated by varying the concentration from x = 10 to 40%. With increasing iron concentration from 10 to 40%, while TC increases from 102 to 160 K higher than the TC of pure CoCr2O4, TS increases from 26 to 40 K. Later transition is clearly shown by sharp transition in specific heat measurement. While enhancement in TC is attributed to increase in lattice expansion and the exchange interaction between tetrahedral (A) and octahedral (B) sites, spin-spiral ordering is dictated by B-B interaction. Further, we have examined the magnetic transitions through neutron scattering using polarized neutron beam along three orthogonal directions. We observe that the para to ferrimagnetic transition is found to be continuous and the spiral ordering is diffused in nature irrespective of composition.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000471650700008
DO  - DOI:10.1016/j.jmmm.2019.165378
UR  - https://juser.fz-juelich.de/record/863217
ER  -