The influence of composition and porosity on the magnetic properties of FeCo-SiO2 nanocomposite aerogels

被引：27
作者：
Casu, Alberto [1 ,2 ]
Casula, Maria Francesca [1 ,2 ]
Corrias, Anna [1 ,2 ]
Falqui, Andrea [1 ,2 ]
Loche, Danilo [1 ,2 ]
Marras, Sergio [1 ,2 ]
Sangregorio, Claudio [3 ,4 ]
机构：
[1] Cittadella Univ, Univ Cagliari, Dipartimento Sci Chim, I-09042 Monserrato, CA, Italy
[2] Cittadella Univ, Univ Cagliari, INSERM, I-09042 Monserrato, Italy
[3] Univ Florence, Dipartimento Chim, I-50019 Sesto Fiorentino, FI, Italy
[4] Cittadella Univ, Univ Cagliari, INSERM, I-09042 Monserrato, CA, Italy
来源：
PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2008年 / 10卷 / 07期
关键词：
D O I：
10.1039/b712719g
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
FeCo-SiO2 aerogel nanocomposites with different porosity were obtained using two different sol-gel procedures: the first involves a single acidic step and gives rise to relatively dense aerogels while the second procedure allows one to obtain highly porous aerogels using urea in the second step to promote fast gelation. Samples with different loading of FeCo equimolar alloy and with different Fe:Co ratios were prepared. The magnetic properties of all the nanocomposite aerogels were extensively studied as a function of porosity and composition. Particular attention was paid to the role played by the interparticle interactions, which are mediated by the silica matrix, in determining the collective magnetic behaviour. The kind and strength of magnetic interactions are affected by both the composition and the porosity of the matrix.
引用
收藏
页码：1043 / 1052
页数：10
相关论文
共 47 条
  • [1] Magnetic properties of CoFe2O4 nanoparticles synthesized through a block copolymer nanoreactor route
    Ahmed, SR
    Ogale, SB
    Papaefthymiou, GC
    Ramesh, R
    Kofinas, P
    [J]. APPLIED PHYSICS LETTERS, 2002, 80 (09) : 1616 - 1618
  • [2] [Anonymous], 1974, X RAY DIFFRACTION PR
  • [3] THE DETERMINATION OF PORE VOLUME AND AREA DISTRIBUTIONS IN POROUS SUBSTANCES .1. COMPUTATIONS FROM NITROGEN ISOTHERMS
    BARRETT, EP
    JOYNER, LG
    HALENDA, PP
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1951, 73 (01) : 373 - 380
  • [4] MAGNETISM FROM THE ATOM TO THE BULK IN IRON, COBALT, AND NICKEL CLUSTERS
    BILLAS, IML
    CHATELAIN, A
    DEHEER, WA
    [J]. SCIENCE, 1994, 265 (5179) : 1682 - 1684
  • [5] Adsorption of gases in multimolecular layers
    Brunauer, S
    Emmett, PH
    Teller, E
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1938, 60 : 309 - 319
  • [6] Structural characterization study of FeCo alloy nanoparticles in a highly porous aerogel silica matrix
    Carta, D.
    Mountjoy, G.
    Gass, M.
    Navarra, G.
    Casula, M. F.
    Corrias, A.
    [J]. JOURNAL OF CHEMICAL PHYSICS, 2007, 127 (20)
  • [7] Role of urea in the preparation of highly porous nanocomposite aerogels
    Casula, Maria F.
    Loche, Danilo
    Marras, Sergio
    Paschina, Giorgio
    Corrias, Anna
    [J]. LANGMUIR, 2007, 23 (07) : 3509 - 3512
  • [8] Near equiatomic FeCo nanocrystalline alloy embedded in an alumina aerogel matrix: Microstructural features and related magnetic properties
    Casula, MF
    Concas, G
    Congiu, F
    Corrias, A
    Falqui, A
    Spano, G
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (50) : 23888 - 23895
  • [9] Characterization of FeCo-SiO2 nanocomposite films prepared by sol-gel dip coating
    Casula, MF
    Corrias, A
    Falqui, A
    Serin, V
    Gatteschi, D
    Sangregorio, C
    Fernández, CD
    Battaglin, G
    [J]. CHEMISTRY OF MATERIALS, 2003, 15 (11) : 2201 - 2207
  • [10] FeCo-SiO2 nanocomposite aerogels by high temperature supercritical drying
    Casula, MF
    Corrias, A
    Paschina, G
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 2002, 12 (05) : 1505 - 1510
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