New method to determine the optical rotatory dispersion of inorganic crystals applied to some samples of Carpathian Quartz

Dimitriu, Dan Gheorghe; Dorohoi, Dana Ortansa

doi:10.1016/j.saa.2014.04.139

Cited by 19 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4) it can be seen a clear differentiation of the quartz belonging to the albite-spodumene pegmatites (sample Q-61), which is more enriched in REE due to the crystallization from a late alkaline-earth-rich fluid, known to have had generated the [18]. The results obtained by the new method [17] using the channeled spectrum of a quartz plate being cut parallel to optical axis are given bellow ( fig. 5).…”

Section: Resultsmentioning

confidence: 99%

“…The highest maxima are obtained in the channeled spectrum when the main axes of the crystalline plate bisect the angle between the transmission directions of the polarizers. The radiations keeping their polarization The wavelengths corresponding to two consecutive minima (λ ok and λ ok+1 ) and those corresponding to the maximum between them can be used to determine the birefringence ∆n in the visible range (in which the polarizers are transparent) [17]: (3) In eq. (3), ∆n is the birefringence (∆n = n e -n o ), L is the thickness of the layer, λ ok and λ ok+1 are the wavelengths corresponding to two consecutive minima of k and k + 1 orders, while λ ok+1/2 is the wavelength of the maximum between them.…”

Section: Optical Considerationsmentioning

confidence: 99%

See 1 more Smart Citation

Optical and Chemical Study of Quartz from Granitic Pegmatites

Androne¹,

Dorohoi²,

Dimitriu³

et al. 2018

Rev. Chim.

Self Cite

View full text Add to dashboard Cite

Of the nine quartz samples collected from the Contu - Negovanu granitic pegmatites (Southern Carpathians, Romania), three were separated under binocular lenses and turned into fine grained powders, for X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) investigation techniques, whilst the other six samples were prepared in thin slides for electron microprobe analyzer (EMPA) and optical investigations, using a Babinet compensator and a Rayleigh interferometer. The results show that the quartz samples belonging to the Contu-Negovanu granitic pegmatites are chemically very pure, showing an expected high participation of silica and only some remarkable contents of Fe, derived from iron oxide micro-inclusions finely disseminated in the quartz grains. The minor and trace elements distribution suggests that different crystallization conditions influenced the quartz composition, thus resulting some rather high contents of Ba, Rb, Sr and some REE contents (Ce) in the pegmatite quartz crystallized from alkali- and alkaline-earth-rich fluids, while the metamorphic quartz appears to be highly pure, showing no such presence. The analyzed quartz samples present birefringence parameters within the limits of other quartz samples and a decrease of the linear birefringence of quartz with the light wavelength increase is emphasized by the data obtained using the channeled spectrum.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Optical Considerationsmentioning

confidence: 99%

Optical and Chemical Study of Quartz from Granitic Pegmatites

Androne¹,

Dorohoi²,

Dimitriu³

et al. 2018

Rev. Chim.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, some measurements were made using Carpathian Quartz [4] in the visible range. This method can be also used in order to determine optical rotatory dispersion of the anisotropic media [5,6].…”

Section: -1mentioning

confidence: 99%

Methods for determining the linear birefringence of some inorganic uniax crystals

Tudose¹,

Dumitrascu²,

Dumitrascu³

et al. 2017

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

Abstract.Anisotropy is an important property of the transparent ordered solids such as crystals, liquid crystals or polymer foils consisting in the dependence of their physical parameters on the propagation direction and light polarization state. The most common birefringent materials are the crystals (including here the liquid crystals) with asymmetric structures and the plastics under mechanical stress. For uniax materials there is a single direction governing the optical anisotropy (called as optical axis), whereas all directions perpendicular to it are optically equivalent. The uniax materials are characterized by two values of the refractive index. The ordinary value (n o ) is measured with linearly polarized radiations acting perpendicular on the principal section, while the extraordinary value (n e ) corresponds to linearly polarized radiations with their electric field intensity contained in this section [1]. Some results obtained by different methods in estimating the main refractive indices and birefringence of some uniax anisotropy layers are given and a comparative study of the accuracy of the applied methods is discussed in this paper.

show abstract

“…For a monochromatic component of the visible range, the rotation angle depends on the circular birefringence c n and on the thickness of the anisotropic layer. [13,14] 0 c nL (1) The circular birefringence is defined as: c l r n n n (2) It is the difference between the refractive indices of the polymer solution measured with circularly polarized radiations to left and to right, respectively. The circular birefringence is a dispersive and material dependent parameter.…”

Section: Theoretical Detailsmentioning

confidence: 99%

“…The method of channeled spectra, initially applied to crystalline, [12][13][14] anisotropic polymer foils [15] or to thin layers of liquid crystals [16,17] in order to determine the linear birefringence, was extended to polymer solutions [18] for estimation optical rotatory dispersion. This is a fast and efficient method to characterize the anisotropy of the transparent layers.…”

Section: Introductionmentioning

confidence: 99%

Optical Rotatory Dispersion of Poly(propylene oxide) in Benzene Solution Determined from Channeled Spectra

Barzic¹,

Dimitriu

Dorohoi

2015

International Journal of Polymer Analysis and Characterization

Self Cite

View full text Add to dashboard Cite

The proposed method of channeled spectrum employs the recorded channeled spectrum of an optical active polymer solution placed between two crossed polarizers. The approach allows the evaluation of the optical rotatory dispersion of poly(propylene oxide) in benzene. The specific rotation, circular birefringence and dispersion parameter depend on the wavelengths of the maxima and minima from the channeled spectrum.

show abstract

New method to determine the optical rotatory dispersion of inorganic crystals applied to some samples of Carpathian Quartz

Cited by 19 publications

References 6 publications

Optical and Chemical Study of Quartz from Granitic Pegmatites

Optical and Chemical Study of Quartz from Granitic Pegmatites

Methods for determining the linear birefringence of some inorganic uniax crystals

Optical Rotatory Dispersion of Poly(propylene oxide) in Benzene Solution Determined from Channeled Spectra

Contact Info

Product

Resources

About