TY - JOUR

T1 - Nanoscale spinel ferrites prepared by mechanochemical route

T2 - TTTThermal stability and size dependent magnetic properties

AU - Šepelák, V.

AU - Heitjans, P.

AU - Becker, K. D.

N1 - Funding Information: The present work was supported by the Deutsche Forschungs-gemeinschaft. Partial support by the Grant Agency of the Ministry of Education of the Slovak Republic and of the Slovak Academy of Sciences (Grant 2/5146/25) and by the Alexander von Humboldt Foundation is gratefully acknowledged.

PY - 2007/10

Y1 - 2007/10

N2 - Among the many types of preparation and processing techniques, the nonconventional mechanochemical route has been recognized as a powerful method for the production of novel, high-performance, and low-cost nanomaterials. Because of their small constituent sizes and disordered structural state, nanoscale materials prepared by mechanochemical route are inherently unstable with respect to structural changes at elevated temperatures. Taking into account the considerable relevance of the thermal stability of nanoscale complex oxides to nanoscience and nanotechnology, in the present work, results on the response of mechanochemically prepared MgFe2O4 and NiFe 2O4 to changes in temperature will be presented. Several interesting features are involved in the work, e.g., a relaxation of the mechanically induced cation distribution towards its equilibrium configuration, a disappearance of the superparamagnetism on heating, an increase of both the saturation magnetization and the Néel temperature with increasing particle size, and a core-shell structure of nanoparticles.

AB - Among the many types of preparation and processing techniques, the nonconventional mechanochemical route has been recognized as a powerful method for the production of novel, high-performance, and low-cost nanomaterials. Because of their small constituent sizes and disordered structural state, nanoscale materials prepared by mechanochemical route are inherently unstable with respect to structural changes at elevated temperatures. Taking into account the considerable relevance of the thermal stability of nanoscale complex oxides to nanoscience and nanotechnology, in the present work, results on the response of mechanochemically prepared MgFe2O4 and NiFe 2O4 to changes in temperature will be presented. Several interesting features are involved in the work, e.g., a relaxation of the mechanically induced cation distribution towards its equilibrium configuration, a disappearance of the superparamagnetism on heating, an increase of both the saturation magnetization and the Néel temperature with increasing particle size, and a core-shell structure of nanoparticles.

KW - Ferrite

KW - Mechanochemistry

KW - Mössbauer spectroscopy

KW - Nanomaterial

KW - Thermogravimetry

UR - http://www.scopus.com/inward/record.url?scp=34648814401&partnerID=8YFLogxK

U2 - 10.1007/s10973-007-8481-1

DO - 10.1007/s10973-007-8481-1

M3 - Article

AN - SCOPUS:34648814401

VL - 90

SP - 93

EP - 97

JO - Journal of Thermal Analysis and Calorimetry

JF - Journal of Thermal Analysis and Calorimetry

SN - 1388-6150

IS - 1

ER -