Phase coexistence and pinning of charge density waves by interfaces in chromium

článek v časopise ve Web of Science, Jimp

angličtina

We study the temperature dependence of the charge density wave (CDW) in a chromium thin film using x-ray diffraction. We exploit the interference between the CDW satellite peaks and Laue oscillations to determine the amplitude, the phase, and the period of the CDW. We find discrete half-integer periods of CDW in the film and switching of the number of periods by one upon cooling/heating with a thermal hysteresis of 20 K. The transition between different CDW periods occurs over a temperature range of 30 K, slightly larger than the width of the thermal hysteresis. A comparison with simulations shows that the phase transition occurs as a variation of the volume fraction of two distinct phases with well-defined periodicities. The phase of the CDW is constant for all temperatures, and we attribute it to strong pinning of the CDW by the mismatch-induced strain at the film-substrate interface.

Charge density waves; Chromium; Phase transition; Thin Films; X-ray diffraction

SINGER, A.; PATEL, S.; UHLÍŘ, V.; KUKREJA, R.; ULVESTAD, A.; DUFRESNE, E.; SANDY, A.; FULLERTON, E.; SHPYRKO, O.

16. 11. 2016

1098-0121

PHYSICAL REVIEW B

94

17

Spojené státy americké

174110-1

174110-5

5

http://doi.org/10.1103/PhysRevB.94.174110