%0 Journal Article %1 WOS:000271542900135 %A de Paiva, J A C %A Graca, M P F %A Monteiro, J %A Macedo, M A %A Valente, M A %C PO BOX 564, 1001 LAUSANNE, SWITZERLAND %D 2009 %I ELSEVIER SCIENCE SA %J JOURNAL OF ALLOYS AND COMPOUNDS %K Ferrite; Magnetic Nanoparticles; Optical Proteic method; properties; properties} solution water; {Coconut %N 1-2 %P 637-641 %R 10.1016/j.jallcom.2009.06.052 %T Spectroscopy studies of NiFe2O4 nanosized powders obtained using coconut water %V 485 %X High-quality NiFe2O4 nanosized powders were prepared by a new route using a natural proteic solution of coconut water and metal ions. The transition from the superparamagnetic to the fernmagnetic state was observed with the increase of the heat-treatment temperature from 400 degrees C to 800 degrees C. In this work, Electron Paramagnetic Resonance (EPR), a.c. magnetic susceptibility(chi(ac)) measurements, infrared (FT-IR) and Raman spectroscopy have been employed to obtain additional information about the structural evolution of the NiFe2O4 nanoparticles, with the increase of the heat-treatment temperature. The obtained results show that the heat-treatment temperature makes remarkable changes in the structure of the samples. The NiFe2O4 nanocrystallite samples, treated at 1200 degrees C, exhibit a large a c magnetic susceptibility which was related with the formation of a mixed spinel phase. This is in agreement with the Mossbauer spectroscopy results The increase of the volume of the nickel ferrite leads to an increase of the magnetic susceptibility. The magnetic properties of these nanoparticles are clearly size dependent. (C) 2009 Elsevier B.V. All rights reserved.

@article{WOS:000271542900135, abstract = {High-quality NiFe2O4 nanosized powders were prepared by a new route using a natural proteic solution of coconut water and metal ions. The transition from the superparamagnetic to the fernmagnetic state was observed with the increase of the heat-treatment temperature from 400 degrees C to 800 degrees C. In this work, Electron Paramagnetic Resonance (EPR), a.c. magnetic susceptibility(chi(ac)) measurements, infrared (FT-IR) and Raman spectroscopy have been employed to obtain additional information about the structural evolution of the NiFe2O4 nanoparticles, with the increase of the heat-treatment temperature. The obtained results show that the heat-treatment temperature makes remarkable changes in the structure of the samples. The NiFe2O4 nanocrystallite samples, treated at 1200 degrees C, exhibit a large a c magnetic susceptibility which was related with the formation of a mixed spinel phase. This is in agreement with the Mossbauer spectroscopy results The increase of the volume of the nickel ferrite leads to an increase of the magnetic susceptibility. The magnetic properties of these nanoparticles are clearly size dependent. (C) 2009 Elsevier B.V. All rights reserved.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, author = {de Paiva, J A C and Graca, M P F and Monteiro, J and Macedo, M A and Valente, M A}, biburl = {https://www.bibsonomy.org/bibtex/2ce32c61413c614572a2f8dc3d0b7c1a2/ppgfis_ufc_br}, doi = {10.1016/j.jallcom.2009.06.052}, interhash = {4967bfef8bbc2348f8faade4828044cc}, intrahash = {ce32c61413c614572a2f8dc3d0b7c1a2}, issn = {0925-8388}, journal = {JOURNAL OF ALLOYS AND COMPOUNDS}, keywords = {Ferrite; Magnetic Nanoparticles; Optical Proteic method; properties; properties} solution water; {Coconut}, number = {1-2}, pages = {637-641}, publisher = {ELSEVIER SCIENCE SA}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Spectroscopy studies of NiFe2O4 nanosized powders obtained using coconut water}, tppubtype = {article}, volume = 485, year = 2009 }