Konfokal Raman yöntemleri
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Dosyalar
Tarih
2010
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Trakya Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Yarıiletken kristallerin, katı çözeltilerin, nano partiküllerin ve seramiklerin mikro-optik özellikleri incelendi. Araştırmalarda Ca2(Mg,Fe)5Si8O22(OH)2, ve Fe3O4 mineralleri, TiO2 nano malzemesi, MgSO4 ve CaCO3 katı çözeltileri kullanıldı. Çalışmada aktinolit (Ca2(Mg,Fe)5Si8O22(OH)2) ve magnetit (Fe3O4) mineralinin Raman titreşimlerini bulduk. Ayrıca, magnetit mineralinin Raman titreşimlerini teorik olarak da hesapladık ve deneysel değerler ile karşılaştırdık. Titreşim işaretlemeleri ve frekansları bulurken Hartree-Fock(HF) yöntemini ve 6-31G(d) baz setini kullandık. Sistemin çizimi, titreşim işaretlemelerinin belirlenmesi ve spektrum çizimi GaussView 5.0.8[A] paket program ile yapıldı. Teorik hesaplama Gaussian 09.A1[X] programı ile linux tabanlı paralel bilgisayarda yapıldı. Magnetitin bağ uzunlukları ve bağ açıları ChemBioOffice2008 programı ile belirlendi. Magnetitin bant yapısı ile enerji aralığını belirledik. Literatürden deneysel frekanslara karşılık gelen modları bulduk. Moleküllerin geometrik yapısı simetri elemanları ve işlemleri hakkında bilgi verir. TiO2 nano malzemelerinin deneysel Raman titreşimleri nano boyutlu malzemeler hakkında bilgi verir. MgSO4 , CaCO3 ve tuz karışımının iki boyutlu taraması elde edildi. GaSe, GaS ve karışık GaSe(1-x)S(x) (0 ? x ? 1) bileşikleri, oda sıcaklığında konfokal düzenekte 632.8 nm dalga boylu He-Ne lazeri kullanarak ölçtük. Sülfür miktarını arttırdıkça kristal yapısında değişiklikler gözlemledik. Ayrıca, sülfür miktarını artması ile şiddet ve pik genişlik değişimlerini inceledik. Genellikle deneysel çalışmalar sonucu elde edilen veriler noktasal değerlerdir. Veriler arasında sürekli bir fonksiyon tanımı yoktur. Böyle durumlarda veriler için sürekli bir fonksiyonun bulunması gerekir. Bu nedenle GaSe1-xSx serili kristalinde x=0, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25 miktarları için deneysel verilerden elde edilen eğrilere fit yaptık. Çalışmada deneysel eğriler inişli çıkışlı olduğundan her bir eğriye parçalı fonksiyon uyguladık. Böylelikle deneysel eğrilerin fonksiyonlarını belirledik. Ayrıca, deneysel ve teorik Raman titreşim frekanslarını karşılaştırdık. Fonksiyon belirlemede Origin8 programını kullandık. Tuz gölü bölgesinde bulunan Helenistik çömlek kırığının siyah ve kızıl pigmentlerinin kimyasal doğası Raman spektroskopisi ile belirlendi. Pigmentlerin belirlenmesi seramiklerin üretiminde hammaddelerin kullanımı için önemlidir. Konfokal Raman spektroskopisi uzamsal konumun bir fonksiyonu olarak Raman çizgilerinin şiddetini ve numunenin kimyasal bileşiminin iki veya üç boyutlu resmini ölçer. 1 mikrondan daha küçük çapa sahip olduğundan diğer spektroskopilere göre daha derine iner. Konfokal Raman spektroskopisi, İnfrared spektroskopisi ve Raman spektroskopisine göre daha iyidir. İnfrared ve Raman spektroskopisi için aktif olmayan zayıf titreşimleri elde ettik. Bu nedenle deneylerde konfokal Raman spektroskopisi kullanıldı.
Abstract
Micro-optical properties were investigated of semiconductor crystals, solid solutions, nanoparticles and ceramics. In the investigations were used Ca2(Mg,Fe)5Si8O22(OH)2 and Fe3O4 minerals, TiO2 nanoparticles, MgSO4 , CaCO3 solid solutions and ceramics. By research was found the Raman vibrations of Ca2(Mg,Fe)5Si8O22(OH)2 (actinolite) and Fe3O4 (magnetite) minerals. Raman vibrations were calculated by theoretically for magnetite and compared with experimental values. We used the method of Hartree-Fock (HF), while finding vibration markings and frequencies and have used the base set of 6-31G(d). Drawing of the system, determination of vibration markings and drawing of spectrum was performed by GaussView 5.0.8[A] package program. Theoretical calculation was done on linux-based parallel computer with Gaussian 09.A1[X] program. Bond lengths and bond angles of magnetite were determined by ChemBioOffice2008 program. We determine the range of energy by band structure of magnetite. By literature was found modes corresponding to experimental frequencies. The geometric structure of molecules gives information about the symmetry elements and processes. Experimental Raman vibrations of TiO2 nanomaterials give information about nano dimension materials. The two-dimensional scan of CaCO3, MgSO4 and salt mixture was obtained. Raman and photoluminescence spectra of GaSe, GaS and mixed compounds GaSe1-xSx (0 ? x ? 1) were measured with a He-Ne laser Landa= 632.8 nm in confocal configuration at room-temperature. We observed the changes of crystal structure by increase the amount of sulfur. In addition, was investigate the changes intensity and peak width for increase the amount of sulfur. Generally, the data obtained as a result of experimental studies are point values. There is not a continuous function definition between the data. In such cases, must be present of a continuous function for data. For this reason, we did fit to curves obtained from experimental data for x=0, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25 amounts in series GaSe1-xSx crystal. In the study, we performed piecewise function due to the curves be bumpy. Thus, the functions of experimental curves were determined. In addition, we compared the experimental and theoretical frequencies of Raman vibrations. The Origin8 was used to determine the functions. The chemical nature of black and redpigments of some Hellenistic sherds from the Tuz Gölü region was identified by Raman spectroscopy. The identification of pigments is important for use of raw materials in the production of ceramics. Confocal Raman spectroscopy measures intensity Raman lines as a function of spatial position and a two or three dimensional image of the chemical composition of the sample. Its diameter is smaller than 1 micron. Therefore, it goes deeper according to the other spectroscopies. Confocal Raman spectroscopy is better than infrared spectroscopy and Raman spectroscopy. We are obtained weak vibrations which not active for infrared and Raman spectroscopy. Therefore, confocal Raman spectroscopy were used in experiments.
Abstract
Micro-optical properties were investigated of semiconductor crystals, solid solutions, nanoparticles and ceramics. In the investigations were used Ca2(Mg,Fe)5Si8O22(OH)2 and Fe3O4 minerals, TiO2 nanoparticles, MgSO4 , CaCO3 solid solutions and ceramics. By research was found the Raman vibrations of Ca2(Mg,Fe)5Si8O22(OH)2 (actinolite) and Fe3O4 (magnetite) minerals. Raman vibrations were calculated by theoretically for magnetite and compared with experimental values. We used the method of Hartree-Fock (HF), while finding vibration markings and frequencies and have used the base set of 6-31G(d). Drawing of the system, determination of vibration markings and drawing of spectrum was performed by GaussView 5.0.8[A] package program. Theoretical calculation was done on linux-based parallel computer with Gaussian 09.A1[X] program. Bond lengths and bond angles of magnetite were determined by ChemBioOffice2008 program. We determine the range of energy by band structure of magnetite. By literature was found modes corresponding to experimental frequencies. The geometric structure of molecules gives information about the symmetry elements and processes. Experimental Raman vibrations of TiO2 nanomaterials give information about nano dimension materials. The two-dimensional scan of CaCO3, MgSO4 and salt mixture was obtained. Raman and photoluminescence spectra of GaSe, GaS and mixed compounds GaSe1-xSx (0 ? x ? 1) were measured with a He-Ne laser Landa= 632.8 nm in confocal configuration at room-temperature. We observed the changes of crystal structure by increase the amount of sulfur. In addition, was investigate the changes intensity and peak width for increase the amount of sulfur. Generally, the data obtained as a result of experimental studies are point values. There is not a continuous function definition between the data. In such cases, must be present of a continuous function for data. For this reason, we did fit to curves obtained from experimental data for x=0, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25 amounts in series GaSe1-xSx crystal. In the study, we performed piecewise function due to the curves be bumpy. Thus, the functions of experimental curves were determined. In addition, we compared the experimental and theoretical frequencies of Raman vibrations. The Origin8 was used to determine the functions. The chemical nature of black and redpigments of some Hellenistic sherds from the Tuz Gölü region was identified by Raman spectroscopy. The identification of pigments is important for use of raw materials in the production of ceramics. Confocal Raman spectroscopy measures intensity Raman lines as a function of spatial position and a two or three dimensional image of the chemical composition of the sample. Its diameter is smaller than 1 micron. Therefore, it goes deeper according to the other spectroscopies. Confocal Raman spectroscopy is better than infrared spectroscopy and Raman spectroscopy. We are obtained weak vibrations which not active for infrared and Raman spectroscopy. Therefore, confocal Raman spectroscopy were used in experiments.
Açıklama
Yüksek Lisans Tezi
Anahtar Kelimeler
Fizik ve Fizik Mühendisliği, Physics and Physics Engineering, Tabakalı Kristaller, Laminated Crystalls
