ChemInform Abstract: The Effect of Heat Treatment on the Microstructure and Magnetic Properties of Sintered Magnets Produced from Nd-Fe-B Based Alloys with and without Cu Substitution.

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.

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Influence of Heat Treatment on the Microstructure and Magnetic Properties of Mn–Sn–Co–N Alloys

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.maw201312 ◽

2013 ◽

Vol 54 (10) ◽

pp. 2007-2010 ◽

Cited By ~ 3

Author(s):

Keita Shinaji ◽

Tsuyoshi Mase ◽

Keita Isogai ◽

Masashi Matsuura ◽

Nobuki Tezuka ◽

...

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Microstructure And Magnetic Properties

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Improvement of Thermal Stability of Nd-Tb-Fe-Co-B Sintered Magnets by Additions of Pr, Ho, Al, and Cu

Physics Research International ◽

10.1155/2012/416717 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

A. A. Lukin ◽

E. I. Il'yashenko ◽

A. T. Skjeltorp ◽

G. Helgesen

Keyword(s):

Heat Treatment ◽

Thermal Stability ◽

Magnetic Properties ◽

Thermal Treatment ◽

Temperature Interval ◽

Magnetic Parameters ◽

Sintered Magnets ◽

Additional Doping ◽

As Solubility ◽

Thermal Stability Of

The present work investigates the influence of Pr, Al, Cu, B and Ho which were introduced into the Co-containing sintered magnets of Nd-Dy-Tb-Fe-Co-B type on the magnetic parameters (α, Hci, Br, BHmax⁡). The effect of heat treatment parameters on magnetic properties was also studied. It was revealed that the essential alloying of NdFeB magnets by such elements as Dy, Tb, Ho, Co as well as by boron-forming elements, for example, by titanium, may lead to reducing of F-phase quantity, and, as a consequence, to decreasing of magnetic parameters. It was also shown that additional doping of such alloys by Pr, B, Al and Cu leads to a significant increase of the quantity of F-phase in magnets as well as solubility of the Dy, Tb, Ho and Co in it. This promotes the increase of magnetic parameters. It was possible to attain the following properties for the magnets (Nd0,15Pr0,35Tb0,25Ho0,25)15(Fe0,71Co0,29)bal ⋅ Al0,9Cu0,1B8,5 (at. %) after optimal thermal treatment {1175 K (3,6–7,2 ks) with slow (12–16 ks) cooling to 675 K and subsequently remaining at T=775 K for 3,6 ks—hardening}: Br=0,88 T, Hci=1760 kA/m, BHmax⁡=144 kJ/m3, α<|0,01|%/K in the temperature interval 223–323 K.

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THE CORRELATIONS BETWEEN HEAT TREATMENT, MICROSTRUCTURE AND MAGNETIC PROPERTIES IN A 2:17 TYPE SAMARIUM: TRANSITION METAL MAGNETIC ALLOY

Magnetic and Superconducting Materials ◽

10.1142/9789812793676_0136 ◽

2000 ◽

Author(s):

A. KIANVASH

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Transition Metal ◽

Magnetic Alloy ◽

Microstructure And Magnetic Properties

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Effect of Heat Treatment on Microstructure and Magnetic Properties of Strontium Hexaferrite Nanoparticles Prepared in Presence of Non-Ionic Surfactant

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.202.193 ◽

2013 ◽

Vol 202 ◽

pp. 193-205

Author(s):

Nital R. Panchal ◽

Rajshree B. Jotania

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Tween 80 ◽

Strontium Hexaferrite ◽

Ionic Surfactant ◽

Treatment Conditions ◽

Heat Treated ◽

Higher Temperature ◽

Co Precipitation ◽

Microstructure And Magnetic Properties

SrFe12O19 hexaferrite particles containing polyoxyethelene (20) sorbitan monolate (Tween-80) were synthesized by a chemical co-precipitation technique with a precipitator NH3.H2O. The prepared Sr-M hexaferrite precipitates were heat treated at various temperatures 650 oC, 750 oC, 850 oC, 950oC and 1100oC for 4 hrs in a muffle furnace. The obtained Sr-M powders were characterized by using various instrumental techniques, like FTIR, TGA, XRD, SEM, VSM and Mössbauer spectroscopy. Their physical as well as Magnetic properties were compared. It was observed from XRD results that heat treatment conditions play significant role in the formation of pure SrFe12O19 hexaferrite phase and also in the grain size. The estimated particle size is of the order of nanometer when suitable calcination temperature is applied. SEM micrographs show an increase in crystallite size of the resultant SrFe12O19 hexaferrite particles sintered at higher temperature (1100 oC). Mössbauer spectroscopic measurements were carried out at room temperature. Mössbauer analysis indicates the presence Fe3+ ions in the prepared strontium hexaferrite particles.

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