Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Preparation and magnetic properties of Ba2Co2Fe28O46 nanocrystals
Autore:
Xiong, G; Mai, ZH;
Indirizzi:
Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China Chinese Acad Sci Beijing Peoples R China 100080 100080, Peoples R China Chinese Acad Sci, Ctr Condensed Matter Phys, Beijing 100080, Peoples R China Chinese Acad Sci Beijing Peoples R China 100080 100080, Peoples R China
Titolo Testata:
JOURNAL OF APPLIED PHYSICS
fascicolo: 1, volume: 88, anno: 2000,
pagine: 519 - 523
SICI:
0021-8979(20000701)88:1<519:PAMPOB>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
BARIUM FERRITE PARTICLES; HEXAGONAL FERRITES; FINE PARTICLES; SIZE; COPRECIPITATION; NANOPARTICLES; DYNAMICS; CLUSTERS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
--discip_EC--
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Xiong, G Chinese Acad Sci, Inst Phys, POB 603, Beijing 100080, Peoples R China Chinese Acad Sci POB 603 Beijing Peoples R China 100080 R China
Citazione:
G. Xiong e Z.H. Mai, "Preparation and magnetic properties of Ba2Co2Fe28O46 nanocrystals", J APPL PHYS, 88(1), 2000, pp. 519-523

Abstract

Ba2Co2Fe28O46 nanocrystals were synthesized through a stearic acid sol-gelmethod. The reaction temperatures were notably lower than that of the conventional ceramic method. The nanocrystalline particles obtained at 750 degrees C were spherical in shape with grain sizes ranging from 10 to 25 nm. Their morphology became more cubic as the heat-treatment temperature was increased. The surface composition of the nanocrystals was found to be different from that of the bulk Ba2Co2Fe28O46, exhibiting a higher content of Ba and Co. The magnetic properties of these samples are clearly size dependent. The specific saturation magnetization is lower than that of bulk Ba2Co2Fe28O46 and inversely proportional to the grain size D. This can be explained by assuming the existence of a nonmagnetic layer on the surface of the particles. The coercivity of Ba2Co2Fe28O46 nanocrystals reaches a maximum when the particle sizes are approximately equal to 70 nm and then decreases by a factor of 3 as the particle size is further reduced. These results are attributed to superparamagnetic effects in a random distribution of single domain ferromagnetic particles. (C) 2000 American Institute of Physics. [S0021-8979(00)04513-8].

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 19:02:26