Issue 10, 1999

Single crystal Raman microscopic study of the asbestos mineral chrysotile

Abstract

Polarisation Raman microscopy is used to study tubular chrysotile. The OH-stretching region is characterised by the inner surface OH bands at 3695, 3686 and 3678 cm-1 and the inner OH band at 3643 cm-1. The outer OH pointing away from the Mg-layer gives rise to two overlapping bands at 3695 and 3686 cm-1 due to a positional disorder caused by the folding of the layers. These bands are the in-phase vibrations whereas the bands at 3678 and 3643 cm-1 represent the out-of-phase vibrations. The 1102 cm-1 band is an antisymmetric stretching mode of Si–O perpendicular to the sheet. From the 692 and 705 cm-1 bands the first one is assigned to the symmetric Si–O–Si stretch and the second to an outer symmetric translation mode of the Mg–OH oriented sub-parallel to the a-axis. The 709 cm-1 band is assigned to the second outer symmetric translation mode of the Mg–OH oriented at a small angle to the b-axis and c-axis. The 629 and 622 cm-1 bands represent antisymmetric OH–Mg–OH translation modes. The band around 607 cm-1 is described as the symmetric libration mode of the inner Mg–OH group. The 458 cm-1 band is assigned as the v3(a1) mode of SiO4. The 466 cm-1 band is probably an OH translational vibration. A strong band at 388 cm-1 is ascribed to the antisymmetric v5(e) mode of the SiO4 tetrahedron. The band at 432 cm-1 is assigned as an antisymmetric Mg–OH translation mode. In the region between 450 and 200 cm-1 five bands can be observed at 374, 345, 318, 304 and 231 cm-1. The 374, 318 and 304 cm-1 bands are antisymmetric modes, whereas the 345 and 231 cm-1 bands are symmetric modes. The band at 374 cm-1 is associated with a symmetric Mg–OH vibration. At present a more detailed assignment of the other bands is not possible. The band at 199 cm-1 is assigned to the A1g mode of a Mg(O,OH)6 octahedron distorted in the direction normal to the octahedral sheet.

Article information

Article type
Paper

Phys. Chem. Chem. Phys., 1999,1, 2559-2564

Single crystal Raman microscopic study of the asbestos mineral chrysotile

J. T. Kloprogge, R. L. Frost and L. Rintoul, Phys. Chem. Chem. Phys., 1999, 1, 2559 DOI: 10.1039/A809238I

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements