Structure of chromium-rich Cr-Ni, Cr-Fe, Cr-Co, and Cr-Ni-Fe alloy particles made by evaporation in argon

Yukawa, Natsuo; Hida, Moritaka; Imura, Toru; Mizuno, Yuta; Kawamura, Masao

doi:10.1007/bf02647663

Cited by 80 publications

(23 citation statements)

References 6 publications

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“…[1][2][3][4][5][6][7][8] For example, Cr particles as small as several hundreds of nanometers exhibit an abnormal A15 metastable phase that has been later found as a high-temperature phase in bulk form. [8][9][10] Analogous behavior has been found also for Co, [1][2][3]7,8,11 where the particles always crystallize in the high-temperature fcc phase that is only stable above 420°C in bulk form. 12 The origin of such an unusual behavior found in Co still remains ambiguous in spite of intensive efforts.…”

Section: Introductionmentioning

confidence: 52%

Size effect on the crystal phase of cobalt fine particles

et al. 1997

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We have synthesized Co fine particles with the average diameter (D) of less than 500 Å by sputtering Co in a somewhat high inert-gas pressure. It has been found that there is a close relationship between the particle size and the crystal phase; that is, pure fcc ͑␤͒ phase for Dр200 Å, a mixture of hcp ͑␣͒ and ␤ phases for D ϳ300 Å, and ␣ phase with inclusion of a very small amount of ␤ phase for Dу400 Å. Precise structural characterizations have revealed that the ␤ particles are multiply twinned icosahedrons and the ␣ particles are perfect single crystals with external shape of a Wulff polyhedron. In order to explain the size effect on the crystal phase of Co fine particles, we have performed theoretical calculations for total free energies of an ␣ single crystal, a ␤ single crystal, and a multiply twinned ␤ icosahedron. The present calculations well explain the size dependence of the crystal phase of the Co fine particles, and have revealed that the stabilization of ␤ phase, confirmed by previous studies, is the intrinsic effect caused by the small dimensionality of fine particles. Moreover, the phase transformations that occurred in annealing experiments can also be explained by the theory. ͓S0163-1829͑97͒05145-X͔

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Section: Introductionmentioning

confidence: 52%

Size effect on the crystal phase of cobalt fine particles

et al. 1997

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“…The same phase with PC structure (A15 type) was found to coexist with s phase in Fe 1Àx Cr x (x ¼ 0:4520:55) alloys produced by vapour quenching [32] and with BCC phase in Fe 1Àx Cr x (x ¼ 0:6521) alloys prepared by thermal evaporation [33].…”

Section: Xrd Resultsmentioning

confidence: 97%

Study of alloying mechanisms of ball milled Fe–Cr and Fe–Cr–Co powders

Bentayeb

Alleg

Bouzabata

et al. 2005

Journal of Magnetism and Magnetic Materials

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“…In the Fe-Cr alloys produced by several vapor deposition methods, evaporation (10), while the A15 phase has been obtained by evaporating Fe and Cr in a high Ar gas atmosphere of about 2.7kPa (20 Torr) and condensing them onto the inner wall of a vacuum chambe (11) . Using a conventional rf sputtering method under an Ar gas pressure, PAr, of 0.53 Pa (4 polyimide film substrates.…”

mentioning

confidence: 99%

“…9(a) and (b) are roughly the same to those of Fe,-x Cr., alloys sputter-deposited on liquid-nitrogen cooled substrates and those of Fe1-xCrx alloys sputter-deposited under PAr=13Pa (10 mTorr). The A15 phase has been obtained in the Cr-rich Fe-Cr fine particles by evaporating Fe-Cr alloys in a very high Ar gas atmosphere (11). In this context, we expect the effect of Ar atoms on the A15 phase formation is the sputter-deposition process.…”

mentioning

confidence: 99%