Position of Incommensurate Satellites Appearing in Ti-Ni Based Shape Memory Alloys

Abstract:

Article Preview

We have investigated electron diffraction patterns of a Ti-44Ni-6Fe alloy exhibitng a negative temperature dependence in electrical resistivity below Tmin = 210 K. The electron diffraction patterns taken near Tmin show diffuse satellites at gB2 + <zζ0>* when the zone axis is [111] and [001]. For both the beam directions, the value ζ is slightly smaller than 1/3. On the other hand, the satellites are missing when the zone axis is [110]. This means that the incommensurate phase has a modulated structure with the propagation vector <zζ0>* (ζ~1/3) and the displacement direction is one of <110> which is vertical to the propagation vector. This modulation is obviously the consequence of the phonon softening of TA2-branch with the propagation vector near <zζ0>* (ζ~1/3). In addition to the satellite at gB2 + <zζ0>* (ζ~1/3), satellites appear at gB2+<zζ0>* with ζ = 1/2 when the zone axis is [001] and rod-like steaks appear in <112>* direction when the zone axis is [110]. However, these satellites and rod-like streaks do not show clear temperature dependence, suggesting they are not directly related to the phonon softening of TA2-branch.

Info:

Periodical:

Solid State Phenomena (Volumes 172-174)

Edited by:

Yves Bréchet, Emmanuel Clouet, Alexis Deschamps, Alphonse Finel and Frédéric Soisson

Pages:

150-154

DOI:

10.4028/www.scientific.net/SSP.172-174.150

Citation:

M. Todai et al., "Position of Incommensurate Satellites Appearing in Ti-Ni Based Shape Memory Alloys", Solid State Phenomena, Vols. 172-174, pp. 150-154, 2011

Online since:

June 2011

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.