J 2013

On the presence of hydrous defects in differently coloured wulfenites (PbMoO4): an infrared and optical spectroscopic study

TALLA, Dominik, Manfred WILDNER, Anton BERAN, Radek ŠKODA, Zdeněk LOSOS et. al.

Basic information

Original name

On the presence of hydrous defects in differently coloured wulfenites (PbMoO4): an infrared and optical spectroscopic study

Authors

TALLA, Dominik (203 Czech Republic, belonging to the institution), Manfred WILDNER (40 Austria), Anton BERAN (40 Austria), Radek ŠKODA (203 Czech Republic, belonging to the institution) and Zdeněk LOSOS (203 Czech Republic, guarantor, belonging to the institution)

Edition

Physics and Chemistry of Minerals, 2013, 0342-1791

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10500 1.5. Earth and related environmental sciences

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 1.403

RIV identification code

RIV/00216224:14310/13:00066884

Organization unit

Faculty of Science

UT WoS

000326056500001

Keywords in English

wulfenite;OH defects

Tags

Tags

International impact, Reviewed
Změněno: 12/2/2014 14:30, doc. RNDr. Zdeněk Losos, CSc.

Abstract

V originále

Several samples of wulfenite, PbMoO4, varying in colour from colourlerss to yellow, orange and red, have been analyzed by means of IR and optical absorption spectroscopy and by microprobe analyses. A distinct pleochroic band group with absorption maxima centred at 3,380 and 3,150 cm-1 can be seen in the IR spectra of wulfenite single-crystals, indicating the presence of hydroxyl groups. The pleochroic and thermal behaviour of the OH stretching bands along with deuteration experiments, as well as results obtained from synthetic fluxgrown samples, exclude the presence of submicroscopic hydrous mineral inclusions as their primary origin. The pleochroic scheme and band positions were used to postulate a model for the OH incorporation mode, based on the assumption of vacancies on Mo and Pb sites in the structure of this ‘nominally anhydrous’ mineral. Optical absorption spectra of coloured natural samples show a broad and polarised band around 23,000-24,000 cm-1, preceding the fundamental UV absorption edge, which has been identified as the reason for the colour of the mineral. The comparison with synthetic PbMoO4, single-crystals, doped with variable amounts of Cr6+, yielded conclusive evidence that trace amounts of the CrO4 2- anion group, substituting for MoO4 2-, determine the variable colour. Besides, in one sample, trace amounts of Nd3+ have been spectroscopically identified.

Links

CZ.1.05/1.1.00/02.0068, interní kód MU
Name: CEITEC - středoevropský technologický institut (Acronym: CEITEC)
Investor: Ministry of Education, Youth and Sports of the CR, CEITEC - Central European Institute of Technology, 1.1 European Centres of Excellence
GAP207/11/0555, research and development project
Name: Oxidy a fosforečnany kovů jako formy jaderného odpadu: studium sonochemického srážení, tepelných přeměn a rozpustnosti (Acronym: OPNW)
Investor: Czech Science Foundation