Nb katkılı BaTiO3 seramiklerin üretimi ve karakterizasyonu
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Dosyalar
Tarih
2014
Yazarlar
Dergi Başlığı
Dergi ISSN
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Yayıncı
Hatay Mustafa Kemal Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Katkılı ve katkısız BaTiO3 seramikleri elektronik devrelerde sıklıkla kullanılır. Bu çalışmada Nb katkılı BaTiO3-bazlı seramikler iki farklı katıhal sentez yöntemi kullanılarak üretilmiştir: I) Geleneksel metot ve II) Ultrasonik karıştırma metodu. Her iki metotta da başlangıç malzemesi bir çözücü içerisinde homojenize edilmiştir. Ardından tozlar kalsinasyon işlemi için fırında tutulmuştur. Kalsinasyon işlemi 1100 oC'de gerçekleştirilmiştir. Tozların fiziksel ve kimyasal analizleri XRD ve SEM ile gerçekleştirilmiştir. Seramik tozlar pellet haline getirilerek 1300 oC'de sinterlenmiştir. Bu pelletler iki metal elektrot arasına yerleştirilerek metal-yalıtkan-metal kapasitör yapıları üretilmiştir. Kapasitörlerin elektriksel karakterizasyonu Agilent E4980A LCR metre kullanılarak belirlenmiştir. Sığa (C) ve kayıp tanjant parametreleri oda sıcaklığında 20 Hz-2 MHz aralığında ölçülmüştür. Ölçülen C-kayıp tanjant değerleri kullanılarak kompleks elektriksel geçirgenlik (ε^'ve ε''), kompleks empedans (Z^(' )ve Z'') ve kompleks AC devresindeki iletkenlik (σ' ve σ'') hesaplanmıştır. Tüm numunelerde empedans parametlerinin değerleri artan Nb katkısıyla değişmiştir. Geleneksel yöntem ile üretilen numunelere ait dielektrik geçirgenliğin reel kısmının, ultrasonik yöntem ile üretilen numunelerin dielektrik geçirgenliğin reel kısmına göre % 10 daha yüksek değerlere sahip olduğu gözlemlenmiştir. Ultrasonik yöntem ile üretilen numunelerin kayıp tanjantı değerlerinin, geleneksel yöntem ile üretilen numunelere göre yaklaşık 2 kat daha düşük bir değere sahip olduğu gözlemlenmiştir. Aynı zamanda kompleks AC iletkenlik (σ' ve σ'') değerlerinin, geleneksel yöntemle elde edilenlerden daha düşük değerlere sahip olduğu görülmüştür. Bu sonuç, ultrasonik metodun sadece elektriksel kaybı değil, aynı zamanda kapasiteyi de düşürdüğü anlamına gelmektedir.
Doped and undoped BaTiO3 ceramics are commonly used in the electronic circuits. In this thesis, BaTiO3-based ceramics with Nb additives were prepared by using two different solid state reaction methods: I) Conventional method and II) Ultrasonic mixing method. In both methods; the starting materials were homogenized in a solvent. Then the powders were kept in a furnace for calcinations process. The calcinations process was carried out at 1100 C. Physical and chemical analyses of the powders were done by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The ceramic powders were pressed into pellets and sintered at 1300 °C. Metal-insulator-metal capacitor structures were produced by placing these pellets in between two metal electrodes. Electrical characterization of the capacitors was measured by using an Agilent E4980A LCR meter. Capacitance (C) and loss tangent parameters were measured in a wide frequency range of 20 Hz- 2 MHz at room temperature. Complex permittivity (ε^' and ɛ''), complex impedance (Z^' and Z'') and complex ac conductivity (σ' and σ'') were calculated by using the measured loss tangent values. The values of impedance parameters changed with increasing Nb additives in all samples. It was observed that the real part of dielctric permitivity of the samples prepared with conventional method was 10% higher than those of the samples prepared with ultrasonic mixing method. It was obtained that the loss tangent values of the samples prepared with ultrasonic mixing method were about two times lower than those of the samples prepared with conventional method. In addition, values of the complex ac conductivity (σ' and σ'') of the samples which were produced by ultrasonic method were less than those of the samples which were produced by conventional method at the same time. It means that the ultrasonic method reduces not only the electrical loss but also the capacity.
Doped and undoped BaTiO3 ceramics are commonly used in the electronic circuits. In this thesis, BaTiO3-based ceramics with Nb additives were prepared by using two different solid state reaction methods: I) Conventional method and II) Ultrasonic mixing method. In both methods; the starting materials were homogenized in a solvent. Then the powders were kept in a furnace for calcinations process. The calcinations process was carried out at 1100 C. Physical and chemical analyses of the powders were done by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The ceramic powders were pressed into pellets and sintered at 1300 °C. Metal-insulator-metal capacitor structures were produced by placing these pellets in between two metal electrodes. Electrical characterization of the capacitors was measured by using an Agilent E4980A LCR meter. Capacitance (C) and loss tangent parameters were measured in a wide frequency range of 20 Hz- 2 MHz at room temperature. Complex permittivity (ε^' and ɛ''), complex impedance (Z^' and Z'') and complex ac conductivity (σ' and σ'') were calculated by using the measured loss tangent values. The values of impedance parameters changed with increasing Nb additives in all samples. It was observed that the real part of dielctric permitivity of the samples prepared with conventional method was 10% higher than those of the samples prepared with ultrasonic mixing method. It was obtained that the loss tangent values of the samples prepared with ultrasonic mixing method were about two times lower than those of the samples prepared with conventional method. In addition, values of the complex ac conductivity (σ' and σ'') of the samples which were produced by ultrasonic method were less than those of the samples which were produced by conventional method at the same time. It means that the ultrasonic method reduces not only the electrical loss but also the capacity.
Açıklama
Anahtar Kelimeler
Fizik ve Fizik Mühendisliği, Physics and Physics Engineering, BaTiO3, Dielektrik, Seramik, Katı-hal sentez metodu., BaTiO3, Dielectric, Ceramic, solid-state synthesis method.
