Publication: Production of nanoscale Ba(Zn1/ 3Nb2/ 3 ) O3 microwave dielectric ceramics by polymerised complex method
Abstract
POLİMERİZE KOMPLEKS METHOD İLE NANOBOYUTTA Ba(Zn1/ 3Nb2/ 3)O3 MİKRODALGA DİELEKTRİK SERAMİKLERİNİN ÜRETİMİ Elektronik seramik grubu içerisindeki dielektrik malzemeler farklı kullanım alanlarına sahip olup, bunlardan biri haberleşme teknolojisidir. Haberleşme teknolojisinde kullanılan dielektrik malzemeler yüksek frekanslarda kullanılmaya uygun mikrodalga dielektriklerdir. Haberleşme sistemlerinde mikrodalga dielektrik seramiklerin temel uygulama alanları rezonatorler ve filtrelerdir. Mikrodalga dielektrik seramiklerin diğer önemli uygulama alanı da çok katlı seramik kapasitörler ve farklı alanlarda ihtiyaç duyulan dedektörlerdir. Mikrodalga dielektrik seramiklerin yüksek dielektrik katsayısına (r>30), düşük dielektrik kayıplarına veya yüksek kalite faktörüne (Q1/ tan>20.000 2 GHz’de), geniş spektral aralıkta iyi bir frekans ve sıcaklık stabilitesine, iyi mekanik ve ısıl stabiliteye sahip olması gerekmektedir. Haberleşme endüstrisinde mikrodalga dielektrik malzeme olarak kullanılma potansiyeli olan seramiklerden biri de Ba(Zn1/ 3Nb2/ 3)O3 (BZN) seramiğidir. BZN seramiği yüksek dielektrik sabitine, düşük dielektrik kaybına ve yüksek dirence sahiptir (r=38, Qf=90 THz). Ancak BZN seramiği 1350 °C gibi yüksek sinterlenme sıcaklığına sahip olup, bu durum BZN seramiğinin Cu ve Ag gibi düşük ergime sıcaklıklı elektrotlarla kullanımını imkansız hale getirmektedir. Ayrıca, BZN seramiğinin rezonans frekans sıcaklık katsayısı (f=30 ppm/ K) relatif olarak yüksek olup, bu durum BZN seramiklerinin mikrodalga uygulamalarında kullanımlarını kısıtlamaktadır. Bu nedenle ütün mikrodalga dielektrik özelliklere ve düşük sinterlenme sıcaklığına sahip BZN seramiğinin üretilmesi bu seramiklerin kullanılma potansiyelini arttıracaktır. Yapılan çalışmada, düşük sinterlenme sıcaklığına sahip BZN seramiklerin üretilmesi amacıyla nano boyutta toz üretimine uygun kimyasal yöntemle BZN seramikleri üretilmiştir. Nano boyutta, aglomerasyon içermeyen homojen dağılıma sahip BZN seramik tozlarının üretilebilmesi için farklı parametreler kullanılmıştır. Üretilen tozlar kimyasal üretimde farklı parametrelerin etkisini vurgulayacak şekilde karakterize edilmiştir.
PRODUCTION OF NANOSCALE Ba(Zn1/ 3Nb2/ 3)O3 MICROWAVE DIELECTRIC CERAMICS BY POLYMERISED COMPLEX METHOD Dielectric materials, a kind of electronic ceramics, have various applications such as communication technology. Dielectric materials used in communication technology are microwave dielectrics, which are applicable at high frequencies. The primary applications of microwave dielectrics in communication technology are resonators and filters. The other important application of microwave dielectrics is multi layer ceramic capacitors and detectors. Microwave dielectric ceramics require high relative permittivity (r>30), low dielectric loss, high quality factor (Q1/ tan>20.000 at 2 GHz), temperature and frequence stability good mechanical and thermal stability. Ba(Zn1/ 3Nb2/ 3)O3 (BZN) ceramic is one of the material that can be used as microwave dielectric in communication systems. BZN ceramic has high dielectric constant, low dielectric loss and high electrical resistivity (r=38, Qf=90 THz). However, BZN ceramics have high sintering temperatures of 1350°C which inhibits them to be co-fired with Cu or Ag electrodes with low melting temperature. In addition, the temperature coefficient of resonant frequency of BZN ceramic is high (f=30 ppm/ K) which restrict the use of these ceramics in microwave applications. In this respect, production of BZN ceramics with superior microwave dielectric properties and low sintering temperatures will encourage the usage of these ceramics. In this study, nanosized BZN ceramics with low sintering temperature were produced by chemical method that is suitable for nanoscale powder production. Various parameters were used to produce nanosized, homogeneous powders without agglomeration. Synthesized powders were characterized to demonstrate the effect of different parameters in chemical processing.
PRODUCTION OF NANOSCALE Ba(Zn1/ 3Nb2/ 3)O3 MICROWAVE DIELECTRIC CERAMICS BY POLYMERISED COMPLEX METHOD Dielectric materials, a kind of electronic ceramics, have various applications such as communication technology. Dielectric materials used in communication technology are microwave dielectrics, which are applicable at high frequencies. The primary applications of microwave dielectrics in communication technology are resonators and filters. The other important application of microwave dielectrics is multi layer ceramic capacitors and detectors. Microwave dielectric ceramics require high relative permittivity (r>30), low dielectric loss, high quality factor (Q1/ tan>20.000 at 2 GHz), temperature and frequence stability good mechanical and thermal stability. Ba(Zn1/ 3Nb2/ 3)O3 (BZN) ceramic is one of the material that can be used as microwave dielectric in communication systems. BZN ceramic has high dielectric constant, low dielectric loss and high electrical resistivity (r=38, Qf=90 THz). However, BZN ceramics have high sintering temperatures of 1350°C which inhibits them to be co-fired with Cu or Ag electrodes with low melting temperature. In addition, the temperature coefficient of resonant frequency of BZN ceramic is high (f=30 ppm/ K) which restrict the use of these ceramics in microwave applications. In this respect, production of BZN ceramics with superior microwave dielectric properties and low sintering temperatures will encourage the usage of these ceramics. In this study, nanosized BZN ceramics with low sintering temperature were produced by chemical method that is suitable for nanoscale powder production. Various parameters were used to produce nanosized, homogeneous powders without agglomeration. Synthesized powders were characterized to demonstrate the effect of different parameters in chemical processing.