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Abstrak :
ABSTRAK
Model dinamis Landau Khalatnikov di gunakan untuk mempelajari energi bebas Gibbs dan kurva histeresis lapisan tipis Barium Zirkonium Titanat (BZT) dengan doping Lantanum dan Indium. Model statis Landau Devonshire juga di pelajari dengan bahan yang sama. Hasil model digambarkan dan dianalisis menggunakan pogram Delphi 6 buatan mandiri yang dijalankan pada Windows. Kedua hasil model dibandingkan dengan kurva hasil eksperimen yang diukur menggunakan rangkaian Sawyer-Tower. Hasil kesesuaian model dan eksperimen di tunjukan oleh R-Weighted Pattern (Rwp), yang merupakan perhitungan satistik untuk menunjukan kesalahan. Beberapa parameter seperti frekuensi, amplitudo medan listrik dan faktor skala divariasikan untuk merubah model secara halus. Hasil menunjukan nilai Rwp kurang dari 10% menunjukan model cukup memuaskan.

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ABSTRACT
Dynamic Landau Khalatnikov model is utilized to study Gibbs free energy and hysteresis curves of Barium Zirconium Titanate (BZT) thin films doped by Lanthanum and Indium. The static Landau-Devonshire was also explored for the same cases. The model is plotted and analysed using home made Delphi 6 program running on Windows platform. Both model is the compared with the experimental hysteresis curves which were measured by using Sawyer-Tower circuit. The matching of the model and experiment is indicated by R-Weighted Pattern (Rwp), which is a statistical number to indicate the discrepancy. By varying the adjustable parameters such as frequency, energy amplitude and scale factor to model was slowly modified. The results showed that Rwp was less than 10% that indicates the model is satisfactory.

Abstrak :
Lapisan tipis Barium Zirkonium Titanat (BaZrxTi1-xO3) dengan doping lantanum telah berhasil ditumbuhkan diatas substrat Pt/Si denga metode sol gel yang dilanjutkan dengan spin coating. Proses yang dilakukan dalam pembuatan lapisan tipis terdiri dari tiga tahap yaitu, pembuatan larutan, proses spin coating, dan proses annealing. Beberapa parameter ditetapkan untuk mendapatkan optimalisasi proses pembuatan lapisan tipis yang meliput jenis substrat, jumlah lapisan, dan temperatur annealing. Optimalisasi didapatkan pada lapisan tipis yang tumbuh pada susbtrat Pt/Si dengan temperatur annealing 800°C. Tingkat kekristalan dan polarisasi listrik spontan optimal pada lapisan tipis BZT didapatkan pada komposisi BaZr0.1Ti0.9O3. Pada variasi jumlah mol dopan didapatkan polarisasi listrik spontan optimum pada 1% mol dopan dengan nilai polarisasi listrik spontan 25 μC/cm2.

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Barium Zirconium Titanate thin films (BaZrxTi1-xO3) doped by lanthanum have been developed in Pt/Si substrates by using sol gel method followed by spin coating. Process was done by three steps which are solvent preparation, spin coating, and annealing process. Optimum parameters were done by varying substrate, quantity of layers, and annealing temperature. The optimum parameters of BZT thin film was found on 800°C for temperature of annealing process, the optimum crystalline film and electrical spontaneous polarization was found on BaZr0.1Ti0.9O3 and doped by 1% mol of lanthanum.

Abstrak :
ABSTRAK
Polianilin telah disintesis melalui polimerisasi oksidatif kimia dengan Ammonium Peroksidisulfat APS sebagai inisiator dalam berbagai konsentrasi 50 g/L, 100 g/L dan 200 g/L . Polimerisasi anilin berjalan dengan ditandai adanya kenaikan temperatur karena reaksi yang terjadi dalam larutan mencapai temperatur tertinggi sebesar 42 C pada larutan dengan konsentrasi APS 200 g/l. Hasil dari reaksi polimerisasi oksidatif berupa basa emeraldin PANi-EB . Struktur PANi dikonfirmasi dengan FTIR ditandai dengan adanya vibrasi stretching pada cincin benzenoid dan quinoid pada bilangan gelombang 1400-1500 cm-1. Sifat konduktif PANi diperoleh melalui pemberian protonasi menggunakan asam kuat yaitu HCl dan HClO4. Nilai konduktivitas PANi-EB mengalami peningkatan 102 kali setelah doping menggunakan HCl dan 106 kali pasca doping HClO4. Semua PANi hasil sintesis memiliki kemampuan penyerapan gelombang elektromagnetik pada rentang frekuensi 10 GHz-15 GHz. Semakin tinggi nilai resistivitas PANi yaitu makin rendah nilai konduktivitas, semakin tinggi juga nilai reflection loss RL . Nilai RL tertinggi sekitar -18 dB pada frekuensi 12,5 GHz dan 14,3 GHz diperoleh dari PANi-EB hasil polimerasi dengan konsentrasi APS sebesar 200 g/l.

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ABSTRAK
Polianiline has been synthesized by chemical oxidative polymerization using Ammonium Polyaniline has been synthesized through chemical oxidative polymerization with Ammonium Peroxidisulfate APS as an initiator in various concentrations 50 g l, 100 g l and 200 g l . The polymerization reactions of aniline are characterized by an increase in temperature due to the reaction occurring in the solution, reaching the highest temperature of 42 C in a solution with APS concentration of 200 g l. Result of oxidative polymerization reaction is the emeraldine base polyaniline or PANi EB. The PANi formation was confirmed by FTIR which characterized by stretching vibrations in benzenoid and quinoid rings at wave numbers 1400 1500 cm 1 respectively. The conductive property of PANi was obtained through doping by a protonation using strong acids HCl and HClO4. It was found that conductivity value PANi EB increased 102 times after doping with HCl and 106 times after doping with HClO4. Moreover, all synthesized PANi has the ability to absorb electromagnetic waves in the frequency range 10 GHz 15 GHz. The higher the resistivity value of PANi that is the lower the conductivity value, the higher the reflection loss RL . The highest RL values of about 18 dB at 12.5 GHz and 14.3 GHz frequencies were obtained from PANi EB polymeration results with APS concentrations of 200 g l.