| 释义 |
ferrite|ˈfɛraɪt|
[f. L. ferr-um iron + -ite.]
1. Min.
a. ‘A name proposed by Vogelsang for the amorphous hydroxide of iron, which in red or yellow particles plays an important part in many rocks, and whose composition is as yet undetermined’ (Dana Min. 1875 App. 11.).
1879Rutley Stud. Rocks x. 167 Ferrite is amorphous red, brown, or yellow earthy matter.
b. ‘An alteration product of chrysolite in the doleryte between Gleniffar and Boyleston near Glasgow, Scotland’ (Dana Min. (1892) 455).
2. Any compound that can be regarded as being formed from ferric oxide and a basic oxide or from ferric hydroxide and a base; esp. any of the compounds with the formula MFe2O4 (where M is a bivalent metal ion or a stoicheiometrically equivalent mixture of such ions), many of which have magnetic properties and a low electrical conductivity that make them suitable for use in high-frequency electrical components.
1851H. Watts tr. Gmelin's Hand-bk. Chem. V. 271 Ferrite of Soda.—78 pts. (1 At.) of ferric oxide mixed with excess of ignited carbonate of soda..form a difficultly fusible mixture. 1897Roscoe & Schorlemmer Treat. Chem. (ed. 3) II. 998 Ferric oxide combines with several basic monoxides to form compounds known as ferrites. 1921J. R. Partington Text-bk. Inorg. Chem. xlviii. 987 With very strong bases unstable ferrites, e.g., Na2Fe2O4, are formed. 1936Physica III. 463 The ‘ferrites’..can be made by thoroughly mixing the finely divided oxide components in powder form, pressing it into a bar and heating the latter for a long time. 1950Proc. Inst. Electr. Engineers XCVII. ii. 238/1 Not all the ferrites are markedly magnetic, zinc and cadmium ferrites being notable exceptions. 1950N. V. Sidgwick Chem. Elements II. 1353 A variety of more complicated ferrites, with more than one Fe2O3 to each M′2O or (more often) M{pp}O, are known. 1955Sci. Amer. Jan. 68/1 The ferrites and the pressed-powder magnets..are now attracting a great deal of attention. 1958N. Cusack Electr. & Magn. Prop. Solids xv. 350 The natural mineral ferrous ferrite is called magnetite and is the original lodestone.
3. Metallurgy. A soft allotrope of pure iron which has a body-centred cubic crystal structure and is stable below 910°C (alpha iron) and above 1403°C (delta ferrite, delta iron); also, a solid solution based on this allotrope, occurring in low-carbon iron alloys as an almost carbon-free constituent.
1888H. M. Howe Metallurgy of Steel in Engin. & Mining Jrnl. 18 Aug. 132 Minerals which compose iron. Name suggested here. Ferrite. Nearly pure iron. 1889,1900[see pearlite]. 1923Glazebrook Dict. Appl. Physics V. 328/2 In commercial iron and steel the ferrite is not pure, but contains dissolved substances, of which the chief are silicon, phosphorus, and manganese. 1957[see alpha 3 d]. 1958Jrnl. Iron & Steel Inst. CXC. 92/2 The ferrites studied..were seven of the Mn–Zn..and two of the Co–Zn type with low Curie points.
4. attrib. and Comb. (in sense 2), esp. ferrite core (core n.1 10, 10 b).
1949RCA Rev. Sept. 392 It is easy to obtain a Q of the order of 50 when using a partially saturated ferrite core. Ibid. 387 The use of ferrite-cored coils permits the use of exciter frequencies up to a few megacycles. 1954E. Molloy Radio & Telev. Engin. Ref. Bk. xiv. 19 The small size of the ferrite-rod aerial makes it suitable for very small receivers. 1964Ann. N.Y. Acad. Sci. CXV. 654 The LINC is a small stored-program digital computer which uses transistor circuitry and a random-access ferrite-core memory. 1965New Scientist 6 May 368/1 The main interest in the wide range of synthetic ferrite crystalline compounds, fashioned by techniques familiar to the ceramics industry, has lain in their widespread use as small components in the telecommunications and electronics industries. 1970Nature 12 Dec. 1039/1 The access time for the present ferrite core store is about 0·5 µs. |