title: Resonant x-ray diffraction study of an unusually large phase coexistence in smectic liquid-crystal films.
abstract: The recent discovery of the new smectic-C(d6)(*) (SmC(d6)(*)) phase [S. Wang et al., Phys. Rev. Lett. 104, 027801 (2010)] also revealed the existence of a noisy region in the temperature window between the SmC(d6)(*) phase and the smectic-C(d4)(*) (SmC(d4)(*)) phase. Characterized by multiple resonant peaks spanning a wide region in Q(Z), the corresponding structure of this temperature window has been a mystery. In this Letter, through a careful resonant x-ray diffraction study and simulations of the diffraction spectra, we show that this region is in fact an unusually large coexistence region of the SmC(d6)(*) phase and the SmC(d4)(*) phase. The structure of the noisy region is found to be a heterogeneous mixture of local SmC(d6)(*) and SmC(d4)(*) orders on the sub-μm scale.
authors.affiliation: School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: LiDong
authors.initials: L
authors.lastname: Pan
authors.forename: P
authors.initials: P
authors.lastname: Barois
authors.forename: R
authors.initials: R
authors.lastname: Pindak
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Liu
authors.forename: B K
authors.initials: BK
authors.lastname: McCoy
authors.forename: C C
authors.initials: CC
authors.lastname: Huang