On the relations between the δ-Cr and α-Cr phases

Bîrjega, M.I.; Popescu-Pogrion, N.

doi:10.1016/0040-6090(89)90031-x

Cited by 13 publications

(2 citation statements)

References 25 publications

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“…An a-BCC Cr film was also analyzed by DSC in the same fashion and the result showed no observable phase change or transformation. It is well known that the common phase that &-A15 Cr is a metastable, allotropic phase as proposed by many earlier studies [2,4,7]. The enthalpy change, AH, of the transformation was not able to be unambiguously determined in this study due to the ill-defined transition completion temperature.…”

Section: A Formation Of Anda15 Cr Filmsmentioning

confidence: 66%

Formation of non-equilibrium sputtered Cr films used in thin film HD recording media

Chu

Chang²,

Lee³

1998

IEEE Trans. Magn.

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Formation and phase transformation of non-equilibrium &-A15 Cr thin films prepared by r.f. magnetron sputtering have been characterized. Processing parameters such as working pressure, deposition time and temperature were found to affect the formation of &-A15 Cr films. We have demonstrated for the first time that the phase transformation of the &-A15 Cr phase to the equilibrium a -B C C Cr phase is an irreversible, exothermic, first-order transition. Onset and peak temperatures of the transformation were determined to be 428°C and 437OC, respectively, at a heating rate of 10"C/min. Our post-deposition annealing study by X-ray diffraction further verified the occurrence of t r a n s f o r m a t i o n .

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Section: A Formation Of Anda15 Cr Filmsmentioning

confidence: 66%

Formation of non-equilibrium sputtered Cr films used in thin film HD recording media

Chu

Chang²,

Lee³

1998

IEEE Trans. Magn.

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“…Chromium forms a body centered cubic (BCC) crystal structure (a-Cr) under equilibrium processing conditions. However, it has been reported [4,5] that an A-15 Cr crystal structure, designated 8-Cr [4], can be formed using PVD techniques. It has also been proposed that the A-15 structure is not an allotrope of Cr but an entirely different phase of suboxide, Cr 3 0 [6].…”

Section: Introductionmentioning

confidence: 97%

Sputter Deposition and Thermally Induced Phase Transformation of Non-BCC Chromium Thin Films

O’Keefe¹,

Horiuchi²,

Chu

et al. 1993

MRS Proc.

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The crystal structure of sputter deposited chromium thin films on Coming 7059 glass, polytetrafluoroethylene, and cold rolled (110) oriented low carbon steel a-Fe substrates was investigated as a function of 0 and C incorporation into the growing Cr film. The as-deposited crystal structure of the films was found by X-ray diffraction to be either highly oriented (110) BCC a-Cr or (200) oriented A-15 8-Cr. Chemical analysis of the films by Auger electron spectroscopy determined that the 8-Cr phase formed when the combined 0 and C impurity concentration in the film was -15-30 at.%. At total impurity concentrations above -30 at.% or below -10 at.% standard BCC a-Cr formed. The crystal structure of the films was not influenced by the substrate material. X-ray photoelectron spectroscopy of the Cr 2pl/ 2 -2p 3 / 2 orbitals indicated that the dominate binding state of both the BCC a-Cr and A-15 8-Cr films was characteristic of elemental Cr. Vacuum annealing of the A-15 8-Cr films at 500WC for one hour transformed the crystal structure into BCC a-Cr without a measurable change in chemical composition. The incorporation of 0 and C into the growing Cr film is believed to impurity stabilize the A-15 structure and favor its formation over the BCC structure.

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