title: X-ray multiple-wave coherent interaction in a quasi-two-dimensional material NbSe2-2H.
abstract: The first observation of the X-ray multiple-wave interaction in an incommensurate charge-density-wave (CDW) modulated structure at low temperatures is reported for an example of a quasi-two-dimensional material, NbSe(2)-2H. Via the coherent interaction between the X-ray waves propagating in the CDW-modulated structure and the host structure, the phase-dependent intensity variations of a CDW reflection were detected. In accord with a centrosymmetric structure, the phases of the structure-factor triplets of two CDW reflections and a Bragg reflection of the host structure were determined to be either 0 or 180 degrees, and not to vary with temperature. Relative phase differences of the two CDW reflections are also deduced.
authors.affiliation: Department of Physics, Tamkang University, Tamsui 251, Taiwan. chd@mail.tku.edu.tw
authors.forename: Chao-Hung
authors.initials: CH
authors.lastname: Du
authors.forename: Mau-Tsu
authors.initials: MT
authors.lastname: Tang
authors.forename: Yuri P
authors.initials: YP
authors.lastname: Stetsko
authors.forename: Yen-Ru
authors.initials: YR
authors.lastname: Lee
authors.forename: Chung-Wei
authors.initials: CW
authors.lastname: Wang
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Cheng
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
mesh_terms: D018360:Crystallography, X-Ray; D008956:Models, Chemical; D009556:Niobium / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013597:Systems Analysis; D013696:Temperature
chemical_list: D018036:Selenium Compounds; D009556:Niobium