title: [XRD and FTIR spectra characteristics of nacreous layer in perna viridis].
abstract: The XRD and FTIR of aragonites in nacreous and prismatic layer of perna viridis were systematically measured, and the frequency variations of v1, v2 and v4 band of aragonites were especially analyzed. The results showed that both of them were aragonite and the frequency of v2 band differed in them, but the frequencies of other two bands were not altered and had the same values with cavernous aragonite. In the same specie of shell, the frequency of v2 band in nacreous layers was greater than that in prismatic layers, and there was a frequency shift of v2 band between them. For the first time, the phase transformation of biogenic aragonite was detected. After nacreous aragonite was heated at 300 degrees C, the frequency shift of v2 band was found. So it is concluded that the biogenic aragonite is related to the thermal effects in crystallizing process, meanwhile it stores excess energy. All of these can provide experiential basis for studying biomineralization theory.
authors.affiliation: College of Chemistry & Chemical Engineering, Guangxi University, Nanning 530004, China.
authors.forename: Tai-Xuan
authors.initials: TX
authors.lastname: Jia
authors.forename: Zi-Li
authors.initials: ZL
authors.lastname: Liu
authors.forename: Gang-Sheng
authors.initials: GS
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002119:Calcium Carbonate / Q000737:chemistry*; D049883:Perna / Q000737:chemistry*; D049911:Pinctada / Q000737:chemistry*; D013028:Space Perception; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013057:Spectrum Analysis; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D002119:Calcium Carbonate