Detection of the onset of nanocrystallization by calorimetric and magnetic measurements

It is generally accepted that measurements of the magnetic properties are more sensitive than measurements of the enthalpy changes in the detection of the onset of crystallization of ferromagnetic phases emerging from a paramagnetic amorphous alloy. In this work, it is shown that the formation of a...

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Detalles Bibliográficos
Autores: Blázquez Gámez, Javier Sebastián, García Franco, Victorino, Conde Amiano, Clara Francisca, Conde Amiano, Alejandro, Roth, Stefan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/33385
Acceso en línea:http://hdl.handle.net/11441/33385
https://doi.org/10.1063/1.1849826
Access Level:acceso abierto
Palabra clave:Field dependence
Magnetization signals
Thermomagnetic gravimetry (TMG)
Vibrating sample magnetometer (VSM)
Calorimeters
Gravimetric analysis
Magnetic properties
Magnetometers
Matrix algebra
Melt spinning
Microstructure
Superalloys
Vitrification
Volume fraction
Nanostructured materials
Descripción
Sumario:It is generally accepted that measurements of the magnetic properties are more sensitive than measurements of the enthalpy changes in the detection of the onset of crystallization of ferromagnetic phases emerging from a paramagnetic amorphous alloy. In this work, it is shown that the formation of a very fine nanocrystalline microstructure can make this assumption incorrect. Under some circumstances, the nanocrystallization onset temperature obtained from magnetic techniques is higher than the one obtained from enthalpy changes. The phenomenon is explained in terms of the superparamagnetic behavior of the uncoupled nanocrystals at the very early stages of nanocrystallization