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Propiedades magnéticas de los cristales de magnetita recristalizados hidrotermalmente
Science (New York, N.Y.)
|June 5, 1987
Resumen
Las propiedades magnéticas de los cristales de magnetita no son inherentes, sino que se ven afectadas por el estrés y la adhesión de fragmentos en granos triturados. Los cristales recristalizados muestran tendencias de tamaño y fuerzas coercitivas siguiendo predicciones teóricas.
Área de la Ciencia:
- La geofísica es la geofísica.
- Ciencia de los materiales Ciencia de los materiales.
- Física mineral Física de los minerales
Sus antecedentes:
- Las propiedades de histeresis magnética de la magnetita difieren entre los granos precipitados y triturados.
- Esta discrepancia se atribuye al estado de tensión y fragmentos adheridos en magnetita triturada.
Objetivo del estudio:
- Para investigar las propiedades inherentes de histeresis magnética de la magnetita.
- Para determinar si las tendencias de tamaño en la magnetita precipitada continúan en cristales más grandes.
- Para comparar las propiedades magnéticas de la magnetita natural, sintética y triturada.
Principales métodos:
- Precipitación de cristales de magnetita de una solución.
- Recristalización hidrotermal de la magnetita. también conocida como recristalización hidrotermal.
- Análisis de las propiedades de histeresis magnética (fuerza coercitiva).
- Examen microscópico mediante el uso de hoyos de dislocación.
Principales resultados:
- Las tendencias de tamaño de las propiedades magnéticas en granos de submicrometro persisten hasta 1 milímetro en cristales recristalizados.
- Las fuerzas coercitivas siguen una ley de potencia a través de un amplio rango de tamaño (0,1 micrómetro a 1 milímetro).
- Las densidades de dislocación son similares en los cristales de magnetita cultivados hidrotermalmente y los naturales.
- Los parámetros de histeresis de los cristales sintéticos coinciden con los naturales, pero son más bajos que los de los granos triturados.
Conclusiones:
- Las discrepancias de propiedades magnéticas observadas se deben a la preparación de la muestra (estrés, fragmentos adheridos), no a las propiedades inherentes de la magnetita.
- Los cristales de magnetita recristalizados hidrotermalmente proporcionan un modelo confiable para estudiar el comportamiento magnético inherente.
- Se validan las predicciones teóricas para el comportamiento de la fuerza coercitiva con el tamaño.
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