| 释义 |
Néel|ˈneɪəl|
The name of Louis Eugène Félix Néel (b. 1904), French physicist, used attrib. to designate certain phenomena connected with his work on magnetism, as Néel point or temperature, the transition temperature for an antiferromagnetic or ferrimagnetic substance, above which it is paramagnetic (analogous to the Curie point for ferromagnetics); Néel spike, a sharply pointed triangular domain extending from a small hole or inclusion in a magnetic substance diagonally in relation to the field direction in the surrounding area; Néel wall, a type of domain boundary that Néel predicted should occur in thin layers of magnetic material, in which the rotation of the field direction in passing from one side of the wall to the other occurs in the plane of the film.
1949Rev. Mod. Physics XXI. 572/2 Measurement of the ratio of length to width of the Néel domains offers a possible experimental method for determining..the surface energy density of a Bloch wall. 1951Jrnl. de Physique et le Radium XII. 311 (heading) Néel ‘spikes’ around holes in a crystal surface. 1952Physica XVIII. 714 In warming the salt through the region of the Néel temperature a continuous but rapid change occurs from a state in which the spins of the Cu++ ions are highly ordered to a state of comparative disorder. 1960Jrnl. Appl. Physics XXXI. 303S/1 The smooth parts of the wall at the thin and thick ends of the film have to be interpreted as pure Néel and Bloch walls, respectively. 1963J. S. Smart in Rado & Suhl Magnetism III. ii. 66 The Néel point..of a ferrimagnet or an antiferromagnet can be determined in a number of different ways, of which magnetic susceptibility is probably the most common and specific heat measurements one of the most accurate. 1966Carey & Isaac Magn. Domains ii. 24 Néel walls become energetically more favourable than Bloch walls for thin films. Ibid. 28 In films of thickness less than about 200 Å no cross-tie walls occur but normal Néel walls are observed. Ibid. viii. 142 Consideration of the magnetostatic energy associated with large inclusions in iron crystals led Néel to predict the existence of closure domains..now termed Néel spikes. 1973Physical Rev. B. VII. 287 (heading) Heat-capacity measurements on manganese dibromide tetrahydrate near its Néel temperature. |