MAGNETIC-PROPERTIES OF SMALL IRON SYSTEMS - FROM FERROMAGNETIC-RESONANCE OF PRECIPITATED PARTICLES IN SILICA TO STERN-GERLACH DEFLECTIONS IN MOLECULAR-BEAM

被引：18

作者：

BILLAS, IML ^{[1
]}

DEHEER, WA ^{[1
]}

CHATELAIN, A ^{[1
]}

机构：

[1] PHB ECUBLENS, ECOLE POLYTECH FED LAUSANNE, INST PHYS EXPTL, CH-1015 LAUSANNE, SWITZERLAND

来源：

JOURNAL OF NON-CRYSTALLINE SOLIDS | 1994年 / 179卷

关键词：

D O I：

10.1016/0022-3093(94)90710-2

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

In silica glass doped with iron and melted under reducing conditions, spherical and non-interacting iron particles are formed by appropriate heat treatments in H-2 gas. Ferromagnetic resonance experiments show superparamagnetic behaviour for particles of sizes ranging from 9 to 15 nm with no modifications of the bulk Curie temperature or magnetocrystalline anisotropy energy. Magnetic moments of iron clusters are investigated from their Stern-Gerlach deflections in a molecular beam, with sizes ranging from 10 to 1000 atoms and temperatures ranging from 100 to 1000 K. Single-sided deflections are found indicating that spin relaxation occurs within the isolated clusters. Superparamagnetic behaviour is observed when the cluster rotational frequency is much larger than the Larmor frequency of the cluster magnetic moment, mu, in the applied field. Marked decreases of mu are observed well below the bulk Curie temperature. At a given temperature, oscillations of mu are observed as a function of size that suggest the filling of layers of atoms in the cluster.

引用

页码：316 / 323

页数：8

共 31 条

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