A method for the preparation of compounds of the type mn3gac with a transition from the antiferromagnetic in a ferromagnetic state and the technical use of these compounds

摘要

1,148,726. Carbides; borides. CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE. 6 May, 1966 [6 May, 1965], No. 20182/66. Heading C1A. [Also in Divisions C7, H1 and H2] A magnetic composition of perovskite structure has the general formula Mn 3-z MSP(1)/SP z Ga 1-y MSP(2)/SPC 1-x Z x wherein MSP(1)/SP is at least one transition metal, (i.e. Sc-Ni, Y-Pd and La-Pr and the lanthanium and actinium series) preferably Cr, Fe, Co, Ni or Pd; MSP(2)/SP is at least one metal of the transition metals, MSP(1)/SP, and Groups IB, II B , IIA, III A and IVA, preferably Mg, Al, Cu, Zn, Ge, Ag, In or Sn; Z is nitrogen and/or boron or is absent; and x, y and z have respective upper limits 0À20, 0À10 and 0À15. The compound has an anti-ferro-ferromagnetic transition point or an anti-ferro-ferri-ferromagnetic transition in the range between -180‹ and - 97‹ C. Specified compositions are: Mn 3 GaC Mn 3 GaC 0À9 N 0À1 Mn 3 GaC 0 . 98 Mn 3 GaC 0À8 N 0À2 Mn 3 GaC 0À97 Mn 3 GaC 0À9 B 0À1 Mn 3 Ga 0À95 Ge 0À05 C Mn 2À94 Fe 0À06 GaC Mn 2À925 Fe 0À075 GaC Mn 2À85 Cr 0À15 GaC 0À95 N 0À05 Mn 3 Ga 0À9 Zn 0À1 C 0À9 N 0À1 The compositions are made by a series of heatings and grindings performed on a mixture of the elements or binary or ternary compounds thereof at temperatures between 300‹ and 900‹ C., the last heating being at 800-900‹ C. in a quartz container and lasting 200 hrs.