Magnetic properties of Sm(Co/sub bal/Fe/sub 0.31/Zr/sub 0.05/Cu/sub 0.04/B/sub x/)/sub z/ alloys and their melt-spun materials (x=0.02--0.04,z=7.5--12)
Cast alloys and melt-spun ribbons with nominal compositions of Sm(Co/sub bal/Fe/sub 0.31/Zr/sub 0.05/Cu/sub 0.04/B/sub x/)/sub z/ (x=0.02-0.04,z=7.5-12) have been synthesized and characterized in a temperature range of 10-1273 K and at fields up to 5T. The main phase in the as-cast alloys exhibited a Th/sub 2/Ni/sub 17/ type structure, with a strong uniaxial anisotropy. Minor phases with a TbCu/sub 7/ and/or CaCu/sub 5/ structure emerged as z (3d/R) decreased. As a result, the anisotropy field (H/sub A/) increased from 67 to 120 kOe, while 4/spl pi/M/sub s/ fell from 12.8 to 10.5 kG at 300 K when z was decreased from 12 to 7.5. For melt-spun ribbons, they are nano-structured in nature and magnetically hard, even in the as-spun state. By lowering the value of z(3d/R) and raising the B content, a finer microstructure and a higher H/sub ci/ were obtained. Hard magnetic properties of H/sub ci/=4.9-12 kOe, 4/spl pi/M/sub s/=9.0-12.0 kG at 300 K have been obtained from ribbon samples. Among them, Sm(Co/sub bal/Fe/sub 0.31/Zr/sub 0.05/Cu/sub 0.04/B/sub 0.02/)/sub 10/ ribbon showed the highest (BH)/sub max/ of 10.8 MGOe at 300 K. A Henkel plot analysis suggested the existence of exchange-coupling interaction between the magnetically hard and soft phases in the ribbon materials.
Structure and magnetic properties of Sm(Co/sub bal/Fe/sub x/Zr/sub 0.05/Cu/sub 0.08/Ga/sub y/B/sub z/)/sub 12/ alloys
3d-rich alloys and their melt-spun materials with nominal compositions of Sm(Co/sub bal/Fe/sub x/Zr/sub 0.05/Cu/sub 0.08/Ga/sub y/B/sub z/)/sub 12/ (x=0.1-0.41, y=0-0.01, z=0.01-0.02) were synthesized and characterized in the temperature range of 10-1473 K and at fields up to 5 T. The main phase of the as-cast alloys was formed in a Th/sub 2/Ni/sub 17/ type structure, exhibiting a strong uniaxial anisotropy. As a result, encouraging hard magnetic properties with T/sub c/=995-1086 K, H/sub a/=40-115 kOe, M/sub s/=10-12.8 kG at 300 K, and H/sub a/=60-180 kOe, M/sub s/=10.4-13.6 kG at 10 K were observed in the as-cast alloys. The melt-spun materials are nano-structured in nature and magnetically hard, even in the as-spun state. The following hard magnetic properties were observed: H/sub ci/=7-10 kOe, 4/spl pi/M/sub s/=9.4-11.7 kG, at 300 K, and H/sub ci/=17-27 kOe, 4/spl pi/M/sub s/=9.6-12.1 kG, at 10 K. The highest (BH)/sub max//spl sim/9.8 MGOe at 300 K was obtained from the Sm(Co/sub bal/Fe/sub 0.31/Zr/sub 0.05/Cu/sub 0.08/B/sub 0.02/)/sub 12/ ribbon material. A Henkel plot analysis indicates the existence of a strong exchange-coupling interaction between the magnetically hard and soft phases in these ribbon materials. The effects of adding Ga, B, and Fe on the magnetic properties will be discussed.
Über die anhysteretische Suszeptibilität magnetischer Einbereichs‐Kollektive
An hartmagnetischen FeNiCr-, FeCoV- und Cunife-Proben wurde die anhysteretische Suszeptibilitat in Abhangigkeit von dem Ausrichtungsgrad der Teilchen, der Packungsdichte und der Koerzitivfeldstarke gemessen. Eine eindeutige Zuordnung wurde nur fur den Ausrichtungsgrad gefunden. Eine Deutung der Ergebnisse mit den verschiedenen theoretischen Vorstellungen bereitet grose Schwierigkeiten. Es sind einige allgemeine Betrachtungen uber das Verhalten von Einbereichs-Kollektiven unter der Einwirkung eines Gleichfeldes mit uberlagertem Wechselfeld angestellt worden. 
 
 
 
The anhysteretic susceptibility of magnetically hard FeNiCr, FeCoV, and “Cunife” alloys is investigated as a function of the degree of alignment, the density of packing of the particles, and the coercitive field. A unique relation is only found for the case of the degree of alignment. The results cannot be fully understood on the basis of the existing theories. A general discussion is given of the behaviour of systems of single-domain particles under the simultaneous action of a d. c. and a. c. magnetic field.