Application of UV-Vis, near-infrared and mid-infrared spectroscopy to the study of Mn-bearing humites
The combination of electronic and vibrational spectra has been applied to correlate the spectral properties, with composition, structure and cation substitutions such as Mn, Fe, Ca and Zn for Mg in humites: norbergite, alleghanyite, leucophoenicite and sonolite with increasing number of silicate layers, 1, 2, 3 and 4. The observation of two broad bands in the visible range, near 550 nm and 450 nm (18180 and 22220 cm-1) and one sharp band around 410 nm (24390 cm-1) is characteristic of Mn2+ in alleghanyite and leucophoenicite. The study of UV-Vis (electronic) spectral features confirms Mn as a major substituent in these two samples. Cation impurities like Zn and Ca as revealed from EDX analysis might be the cause for the absence of Mn-type spectrum in sonolite. The first observation is the near-infrared spectra of all four minerals in the first fundamental overtone OH-stretching mode are different and each mineral is characterized by its NIR spectrum. The feature in the range 7180-6600 cm-1 [1393 to 1515 nm or 1.39 to 1.52 µm] corresponds to the overtones of OH stretching vibrational modes of the humite groups observed in their IR spectra over the range, 3680-3320 cm-1. The infrared spectra of the hydrous components of OH and SiO4 groups in the mineral structure act as an aid to distinguish the minerals of the humite mineral group. A band at 541 cm-1 is assigned to MnO stretching mode.
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.
|Item Type:||Journal Article|
|Keywords:||Norbergite, Alleghanyite, Leucophoenicite, Sonolite, UV, Vis, NIR and mid, IR spectroscopy, Electronic spectra of Mn2+, Overtone and combination bands, Layered silicates|
|Subjects:||Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000)|
|Divisions:||Past > QUT Faculties & Divisions > Faculty of Science and Technology|
|Copyright Owner:||Copyright 2007 Elsevier|
|Copyright Statement:||Reproduced in accordance with the copyright policy of the publisher.|
|Deposited On:||02 Feb 2007 00:00|
|Last Modified:||05 May 2014 23:44|
Repository Staff Only: item control page