Short range order in Ni{sub 4}Mo and its high resolution electron microscope images

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00180-3· OSTI ID:669794

Hata, S; Matsumura, S; Kuwano, N; Oki, K ^[1]; Shindo, D ^[2]

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1. Kyushu Univ., Fukuoka (Japan)
2. Tohoku Univ., Sendai (Japan). Inst. for Advanced Materials Processing

The short range ordered (SRO) structure in Ni{sub 4}Mo has been investigated by means of high resolution transmission electron microscopy with digital image processing and Monte Carlo simulation. High resolution transmission electron microscope (HRTEM) images were recorded with an Imaging Plate (IP) system. Conventionally printed images of the SRO state exhibit locally dot patterns corresponding to N{sub 2}M{sub 2}-type (chalcopyrite-like) structure. However, the dot patterns transform into those of subunit cell clusters of D1{sub a}, D0{sub 22} and Pt{sub 2}Mo structures, when the image is output with a different gray scale. The Monte Carlo simulation with appropriate interaction parameters of atoms has explained successfully the HRTEM images. It is concluded that the SRO state in Ni{sub 4}Mo involves subunit cell clusters of D1{sub a}, D0{sub 22} and Pt{sub 2}Mo structures in the atomistic level of microstructure. The concept of <1 1/2 0> static concentration waves corresponding to the N{sub 2}M{sub 2} pattern is rationalized as a mesoscopically averaging view of the SRO state.

• OSTI ID: 669794
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 14 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IMAGE PROCESSING
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
MOLYBDENUM ALLOYS
MONTE CARLO METHOD
NICKEL ALLOYS
SIMULATION
TRANSMISSION ELECTRON MICROSCOPY