Vibrational spectroscopic study of muscovite and biotite ... - NOPR

Indian Journal of Pure & Applied Physics Vol. 54, February 2016, pp. 116-122

Vibrational spectroscopic study of muscovite and biotite layered phyllosilicates Mohan Singhaa,* & Lakhwant Singhb a

Department of Physics, Khalsa College, Amritsar 143 005, India Department of Physics, Guru Nanak Dev university, Amritsar 143 005, India

b

Received 2 March 2015; revised 12 August 2015; accepted 5 November 2015 In the present paper, the muscovite and biotite phyllosilicates minerals from the Nilore mica belt, India, have been studied using a combination of different techniques. Vibrational spectroscopy enables an assessment of the molecular structure of muscovite and biotite silicates and helps to understand their complex structures which will be useful for various scientific and industrial applications. The present results have been well compared with the published data for the correspondent minerals of different origins. Keywords: Vibrational spectroscopy, Muscovite, Biotite, Phyllosilicates

1 Introduction Natural silicate minerals have focused the interest of many research groups because of their technological applications like nanotechnology, material science, electrical engineering, high temperature and advanced power electronics, spacecraft, supersonic aircraft, dosimetry and radiation research1-11. There are several kinds of natural silicates, with distinct properties, but phyllosilicates especially mica family are, in general, very stable and has tremendous applications in science and technology2-12. Mica has a distinct layered crystal like structure, and easily cleave into very thin, optically flat sheets. Unique properties (low dielectric loss, best for mica capacitors, perfect cleavage, high flexibility, good physico-chemical stability at high voltages and temperature etc) of these mica phyllosilicates, make it an appropriate material for various cutting edge scientific and industrial applications. There are many types of mica, but muscovite and biotite are the cheapest, easily available and have better properties as compared to other mica silicates, which make them useful for various technological applications. Therefore, it is important to understand deeply the various characteristics of these types of emerging materials. Vibrational spectroscopic technique has proven most powerful tool to study the materials structure especially natural minerals structure12-27. In recent years, spectroscopic studies of phyllosilicates minerals have been increasing, especially due to their ——————— *Corresponding author (E-mail: [email protected])

industrial and technological importance. The authors have already studied irradiation induced effects and defects, dielectric relaxation characteristics, thermoluminescence characteristics of these types of phyllosilicates2-11. Several studies have been so far undertaken to describe the vibrational spectra of muscovite but rare published research work is available for biotite mica. So, in the present paper, the vibrational spectral characteristics of muscovite and biotite sheet silicates have been studied. An attempt was made to correlate the spectral characteristics of these two minerals with their structural features. The obtained infrared and Raman spectra have been interpreted and the results have been compared with the data published by different researchers for the analogous mineral species from different origins. This type of investigation will provide information and opportunities for various industrial applications and as well as the better understanding of the mica. 2 Mica Phyllosilicates Mica phyllosilicates have monoclinic nature, with unit structure consists of one octahedral sheet between two opposing tetrahedral sheets. This type of silicates crystallizes in a layered structure and cleaves easily into very thin sheets. These thin sheets form a layer that is separated from adjacent tetrahedral and octahedral layers by planes of non-hydrated interlayer cations. The tetrahedra present in silicates structures consisting of four oxygen atoms arranged to occupy the corners of a tetrahedron with a silicon atom in the

SINGH & SINGH : VIBRATIONAL SPECTROSCOPIC STUDY OF MUSCOVITE AND BIOTITE LAYERED PHYLLOSILICATES

centre. The oxygen atoms are shared between adjacent tetrahedra to form sheets that are combined in tetrahedral sheet (TsOs ) and octahedral sheet (TsOTs) layers. The simplified formula of mica silicates can be written as: IX2-3Δ1-10T4O10Z2 where I is the interlayer cations (e.g., Cs, K, Na, NH4, Rb, Ba and Ca), X is octahedrally coordinated cations (e.g., Li, Fe, Mg, Mn, Zn, Al, Cr, V and Ti), Δ represents a vacancy, T is commonly Be, Al, B, Fe and Si and Z is commonly Cl, F, OH, O and S. There are three major divisions within the mica silicates, i.e., the true micas, the brittle micas and the interlayer-deficient micas. This division is further divided into dioctahedral (e.g. muscovite, boromuscovite, etc) and trioctahedral groups (e.g. biotite and phlogopite). In the present paper, sheets of muscovite and biotite natural micaceous minerals collected from Nilore mica belt, India have been used. These are known to be very good dielectric and simple sample preparation (easily cleavage which gives atomically flat surfaces without any detectable defects). The muscovite mica silicates ( = 2.800 g/cm3; crystallographic system: monoclinic; di-octahedral) has layered structure consisting of series of sheets stacked parallel to each other. Its structure consists of infinite sheets of corner-shared SiO4 tetrahedra, with the apical oxygen atoms located at the corners of a hexagon. One-fourth of Si atoms is replaced by Al, with the remaining K+ and Al3+ ions lying between the aluminosilicate sheets. A octahedral AlO6 sheet is sandwiched between two tetrahedral SiO4 sheets, with a layer of interlayer K+ ions. The ionic bonding between the K+ ions layers and the trilayer aluminosilicate sheet is rather weak, so it cleaves easily at the positions of the K+ ions. Biotite mica (= 2.900 g/cm2; crystallographic system: monoclinic) is common rock forming silicate mineral. It is tri-octahedral mica, in which some of the Mg2+ is replaced by Fe2+, and in phlogopite (which is also tri-octahedral mica), all the three possible octahedron cations are replaced by Mg2+. Other substitutions may include Ca2+, Ba2+ and Cs+, Na+ for K+ and F– for OH–. The typical black to brown colour of this mica is the main characteristic although it is difficult to distinguish brown biotite mica from dark brown phlogopite mica.

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In the present paper, sheets of muscovite and biotite natural micaceous minerals collected from Nilore mica belt, India have been used. These are known to be very good dielectric and simple sample preparation (easily cleavage which gives atomically flat surfaces without any detectable defects). 3 Experimental Details Very flat and thin sheets of muscovite and biotite micas were prepared by perfect cleaving the natural bulk samples collected from the Nilore mica belt, India. The compositional analysis of thin cleaved flat sheets of the “as received” samples were carried out using the Electron Probe Microanalyser (EPMA) installed at IIT Roorkee, India. The results of the microprobe analysis for both muscovite and biotite samples have been presented earlier4,5,7. The XRD patterns of muscovite and biotite micas were taken with PANalytical XPert PRO diffractometer installed at Panjab University, Chandigarh, India. The XRD patterns for the chosen muscovite and biotite silicates are shown in Figs 1 and 2, respectively. From the observed XRD patterns of the samples, various lattice parameters for muscovite and biotite have been calculated and presented in Tables 1 and 2, respectively. The Shimadzu Fourier transform infrared spectroscopy (FTIR) system was employed for recording the spectra of the chosen phyllosilicates. The observed FTIR spectrum for muscovite and biotite mica samples are shown in Figs 3 and 5, respectively. The Raman measurements were performed using argon laser with excitation line 514.5 nm (Renishaw). The observed Raman spectra for muscovite and biotite mica samples are shown in Figs 4 and 6, respectively.

Fig. 1 – X-ray diffraction pattern of muscovite mica

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INDIAN J PURE & APPL PHYS, VOL 54, FEBRUARY 2016

Fig.2 – X-ray diffraction pattern of biotite mica Table 1 – Observed crystallographic parameters of muscovite mica a= 5.1918, b = 9.0153, c = 20.0457, β = 95.74 [28] a = 19.9733, b = 9.0601, c = 5.2261, β = 95.81 [12] a=5.0983; b=9.1877; c=19.9228; β=93.48 [Present work] 2θ d (Å) hkl 9.000 9.818 002 17.908 4.949 004 26.924 3.308 006 26.975 3.303 006 36.113 2.485 008 36.253 2.476 132 45.555 1.989 029 45.718 1.983 -2 2 5 55.375 1.658 -2 4 4 55.524 1.654 240 65.575 1.422 1 1 13 65.790 1.418 -2 2 11 76.413 1.245 350 76.691 1.242 2 0 14

4 Results and Discussion The electron microprobe chemical analyses for present samples have been presented earlier4,5,7, which confirm that our chosen materials are muscovite and biotite mica phyllosilicates. The weight % for muscovite mica was Na2O (0.68%), MgO (0.16%), Al2O3 (35.17%), SiO2 (47.00%), K2O (10.49%), TiO2 (0.02%), FeO (2.29%), MnO (0.03%) and for biotite the weight % was Na2O (0.21%), MgO (3.76%), Al2O3 (19.42%), SiO2 (33.77%), K2O (8.32%), TiO2 (2.15%), FeO (25.23%), MnO (0.17%)4,5,7. The chemical formulae of the studied muscovite and biotite micas can be expressed as

Fig. 3 – Infrared spectrum of muscovite mica Table 2 – Observed crystallographic parameters of biotite mica a= 5.3000, b = 9.2100, c = 10.1600, β = 99.50 [29] a = 10.2255, b = 9.2558, c = 5.3520, β = 100.21 [12] a=5.2992; b=9.1956; c=10.1703; β=98.09 [Present work] 2θ d (Å) hkl 8.839 9.996 001 17.664 5.017 002 17.837 4.969 002 26.587 3.350 003 26.855 3.317 112 35.683 2.514 -2 0 1 36.047 2.490 130 45.020 2.012 133 45.131 2.007 133 45.495 1.992 133 45.608 1.987 222 54.691 1.677 320 54.828 1.673 310 64.803 1.438 330 64.995 1.434 330 75.522 1.258 137

[(K0.87Na0.08)Σ0.95(Al 1.98Mg0.02)Σ2.00(Al0.72Fe3+0.25Si3.06) and [K0.88Na0.03(H2O)0.08]Σ0.99 Σ4.03O10(OH)1.81] (Fe1.75Mg0.46Al0.84Mn0.01)Σ3.07(Al1.06Ti0.13Si2.81)Σ4.00O10 (OH)2.00(H2O)0.85}, respectively4,5,7. For the identification purpose, the XRD of these two silicates minerals (muscovite and biotite) were performed and shown in Figs 1 and 2. The unit cell crystallographic parameters (Tables 1 and 2) for the present minerals are in better agreement with the data published by other researchers12,28,29. For muscovite mica, the unit cell parameters are in better comparison with the data published by Rothbauer28, but unit cell parameters


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Fig. 6 – Raman spectrum of biotite mica Fig.4 – Raman spectrum of muscovite mica

Fig. 5 – Infrared spectrum of biotite mica

a and c for the present muscovite mica are oppositely arranged as compared to the data of Sontevska et al.12. In case of biotite mica, our present unit cell parameters show better agreement with the unit cell parameters published by Hendricks and Jefferson29, similarly unit cell parameters for present biotite mica are oppositely arranged as compared to the corresponding parameters published by Sontevska et al.12 . The infrared absorption spectrum in the region 4000 - 400 cm-1 of muscovite mica is shown in Fig. 3. The infrared spectrum of the studied muscovite sample is characterized by different bands that appear in two well-defined spectral regions originating from OH and SiO4 vibrations12,

respectively (Fig. 3). In the OH stretching region, a band with medium intensity is registered around 3622 cm-1 and attributed to the stretching vibrations of the OH groups, which is supported by data published by other researchers12-16,21. In addition, a strong and broad band was observed near 3426 cm-1 which may be originated due to H2O stretching vibrations from the adsorbed water. Many researchers claimed the presence of the adsorbed water by the observation of weak band around 1630 cm-1 assigned to δ(H2O) vibrations, but in case of our present muscovite mica, a strong band is observed near 1599 cm-1. As a comparison or as a support for our present results, the data published by other researchers are also presented in Table 3. The tentative assignment for different bands in the vibrational spectrum of studied muscovite mica is presented in Table 3. The bands at 1063 and 1028 cm-1 belong to νas(Si–O), which are also in better comparison with the literature data. The shoulders at 993 and 926 cm-1 are due to the stretching Si-O-Si mode and comparable with the data published by other researchers. Whereas the shoulder near 910 cm-1 and medium intensity bands near 405-409 cm-1 arise due to the Al-O-Al librational mode. The bands in the region 827-727 cm-1 are assigned to Al-O and Al-O-Al stretching modes. The infrared bands in the range 685-476 cm-1 appear from the δ(Si-O-Al) and δ(Si-O-Si) possibilities. From the present investigation, it is checked that the infrared results for muscovite mica show better agreement with the results published by other researchers for muscovite micas with different origins12-16,21 .

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The Raman spectrum in the region 1200 - 100 cm-1 for muscovite mica is shown in Fig. 4. Table 4 presents the tentative assignment for different bands in the Raman spectrum of studied muscovite mica and different spectral results published in literature12,18-20. The obtained Raman results for the studied muscovite mica are in better agreement with the data published by many researchers in literature regarding the muscovite mica from different origins12,18-20 (Table 4). In higher frequency region, a very strong band around

1127 cm-1 and the medium intensity band around 914 cm-1 belong to stretching Si-O-Si and Si-O-Al vibrations. The medium intensity band near 755 cm-1 and 703 cm-1 arise from the δ(O-Al-O) vibrations. Due to the bending character of Al-O-Al, a band at 579 cm-1 is observed in Raman spectrum of muscovite. The lower frequency strong bands around 407 cm-1 and 263 cm-1 are linked to the O-Al-O and O-Si-O translations. Due to the Al-OH translations, a medium intensity Raman peak is also observed near 197 cm-1.

Table 3 – Bands in the infrared spectrum of muscovite mica Present work

Sontevska et Sontevska et al.12, (Dunje) al.12, (Nezilovo)

3622m 3426s,b 1599vs 1188m 1063sh 1028vs 993sh 926sh 910sh -

3615m 3430vw 1630vw 1078sh 1025vs 1001sh,s 910w -

827w 800w 783m, 754m 708vw, 727sh

827w 748w -

3610m 3422w 1630w 1076sh 1022vs 999sh,s 908w 825w 801vw 746w 692vw 624sh 557sh 519s 470s 415s -

Taylor et al.13,

Veder & McDonald14

Stubican & Roy15

Zeller & Juszli16

Langer et al.21,

Tentative Assignment

3640w 3430vw 1630vw 1065sh 1020vs 920sh 822w 795vw 765w -

3628m 1120w 1070sh,s 1024vs 985sh,s 928m 827m 805w 755w -

3620m 1080sh 1020vs 915w -

3630m 3420w 1630w 1070sh 1020vs 920sh -

1113 1065 1028 996 937 912 877

ν(OH) ν(H2O) δ(H2O)

820w 800vw 760w -

825w 755m -

831 805 751 727

ν (Al-O) ν(Al-O-Al) ν(Al-O-Al)

535s 475s 405w -

690w 535s 475s 405s -

700 619 580 553 539 520 480 410 381

δ(Si-O-Al) δ(Si-O-Si)

685w 690vw 691w sh sh 629 626 630w 552sh 558sh 538m 530s, 513sh 521s 538s 528s 476s 472s 472s 472s m m s m 405 , 409 416 410 408s s w m sh v LM Strong; Weak; : Medium; Shoulder; Very; Librational mode

νas(Si-O) νas (Si-O) ν(Si-O-Si) L(Al-O-H)LM

δ(Si-O-Si) δ(Si-O-Si) δ(Si-O-Si) L(Al-O-H)LM

Table 4 – Bands in the Raman spectra of muscovite mica Present work Sontevska et Sontevska et Sontevska et Sontevska et Wada & al.12, al.12, al.12, al.12 Kamitakahara18 (Dunje)@ (Dunje)@ (Nezilovo)$ (Nezilovo)$ 1127vs 1097vw,br 1102w 1097w 914m 900vw 899w 902vw 902vw 895w 755m 752vw 753vw 751vw 752vw 755vw 703s 703s 701s 701s 698m 705s vw w 579 541 407s 419m,br 420m,br 420m 420w 425s 263vs 262vs 262vs 262s 262s 270vs m m m w w 197 191 191 188 188 200m @ Excitation with the 532 nm; $ Excitation with the 1064 nm s Strong; w Weak; m Medium; v Very; sh Shoulder; br Broad

McKeown et al.19,

Wopenka et al.20,

Tentative assignment

1098w 912w 754w 704s 542w 410s 265vs 199m

914w 756w 706s 566w 417s 263vs 195m

ν(Si–O–Si) ν(Si–O–Al) δ(O–Al–O) δ(O–Al–O) δ(Al–O–Al) δ(O–Al–O) δ(O–Si–O) L(Al–OH)


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Table 5 – Bands in the infrared spectra of biotite mica Present work

Sontevska et al.12, (Caniste)

Sontevska Zeller & Juszli16 FDM spectra17 12 et al. , (Pelagon) (Canada)

3792m 3675w m m 3541 3556 3555m s m 3410 3427 3374m 1599vs 1639w s vs 1003 1015 1002vs m m 766 727 718w sh m 633 682 681m s vs 476 , 455 457vs s w m v sh strong; weak; medium; very; shoulder.

3650w 3420w 1625w 1010vs 725w 680w 460vs

FDM spectra17 (Ontario)

Tentative assignment

3684vw 3430w 1629w 1005vs 725w 682w -

ν(OH) ν(OH) ν(H2O) (adsorbed water) ν(H2O) (adsorbed water) δ(H2O) (adsorbed water) ν(Si–O–Si) ν(Al–O–Si) ν(Si–O–Si) ν(Si–O–Si)

3705w 3429w 1624w 1001vs 721sh 688w -

Table 6 – Bands in the Raman spectra of biotite 12

Present work Sontevska et al. (Pelagon)@ Sontevska et al.12, (Caniste)@ Ref.(26) Ref.(27) m w 1130 1093 1096w 1100w 767m, 715m 760m 685w 673s 669m 670m 690 552s 587s 588s 560s w m w 354 354 371 370m 313w 309m 310 273w 292w 270w 275 s vs s 182 183 189 190 143w 148w 140w 106w 104 @ Excitation with the 532 nm; s Strong; w Weak; m Medium; v Very; a M = Mg or Fe; TM Translational mode

The infrared absorption spectrum in the region 4000 - 400 cm-1 of biotite mica is shown in Fig. 5. Table 5 presents the different bands observed for the present biotite and data published by various researchers for biotite micas of different origins with tentative assignment for each band12,16,17. The observed IR spectrum of biotite (Fig. 5 and Table 5) clearly demonstrates the presence of strong bands near 3410 cm–1 due to adsorbed water, but in literature this range of absorbance bands is between 3374 to 3430 cm-1. The presence of adsorbed water is also confirmed from the very strong band observed near 1599 cm-1, other researchers claimed that this band region is between 1624 cm-1 to 1639 cm-1. The bands registered at 3541 cm-1 and 3792 cm-1 in the spectrum of present biotite sample are evidence for the presence of OH groups. The intense band in the spectrum of biotite is observed near 1003 cm-1 which may be related to the ν(Si–O–Si) vibrations and in a very good agreement with the corresponding literature data12,16,17 (Table 5) . Another infrared shoulder near 633 cm-1 and strong band near 476 cm-1 can also be

Tentative assignment ν(Si–O–Si) δ(Si–O–Si) δ(Si–O–Si) T(M–O)a, TM T(M–O) T(M–O) T(M–O) T(K–O) T(K–O)

assigned to vibrations related to ν(Si–O–Si). The band12,16,17 around 720 cm-1 is assigned to the ν(Al–O–Si) vibrations, but in case of present biotite, it is observed at 766 cm-1. The observed infrared bands for the present biotite are in close agreement with the published data available in the literature. The Raman spectrum in the region 1200 - 100 cm-1 of biotite mica is shown in Fig. 6. Table 6 presents the tentative assignment for different bands in the Raman spectrum of present biotite mica from different origins and data published in literature. The obtained Raman results for the present biotite mica are in better agreement with the data published by many researchers in literature regarding the biotite micas from different origins12,26,27 (Table 6) . The highest-frequency peaks are in the range 1093 1100 cm-1 in biotite spectra as a result of ν(Si-O-Si) mode of vibration, but in case of present biotite sample, this band is observed at medium intensity peak at 1130 cm-1. In our present biotite mica, another medium intensity peaks are found near 715 and 7 67 cm-1. The most intense bands near 552 cm-1 and

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weak peak at 685 cm-1 in the biotite spectrum belong to the Si-O-Si bending. The bands originating from the translational (Mg-O, Fe-O) modes produce bands between the range 354 - 182 cm-1 (Table 6). 5 Conclusions The muscovite and biotite phylosilicate minerals have been analyzed from the Nilore mica belt, India using electron probe, X-ray diffraction, infrared spectroscopic and Raman spectroscopic techniques. It is concluded that the vibrational spectroscopy gives significant information about important muscovite and biotite phyllosilicate minerals. Due to the complex chemical substitutions and complicated crystal structures, some difficulties remain unsolved, which cannot be easily solved only with vibrational spectroscopy. It is concluded that Raman spectroscopy is found to be more powerful technique to study different minerals of different origins and impurities.

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