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

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

WoS Article

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.

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

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.

2017

16.11.2016

1098-0121

PHYSICAL REVIEW B

94

17

United States of America

174110-1

174110-5

5

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