Judul: Analysis of Saturation Current, Barrier  Voltage, and Electron Mobility of Ferium-Doped Barium Titanate Thin Films
Abstrak: Perkembangan teknologi khususnya elektronika gencar dilakukan untuk menciptakan inovasi devais berukuran kecil dengan performa yang maksimal, seperti film tipis. Film tipis Barium Titanat (BaTiO3) didadah Ferium dengan variasi konsentrasi pendadah (0%; 0,5%; dan 1%) berhasil dibuat. Larutan sampel disaring menggunakan filter PVDF kemudian dideposisi menggunakan metode chemical solution deposition (CSD) di atas substrat silikon tipe-p (100) dengan teknik spin coating pada kecepatan putar 3000 rpm selama 60 detik. Proses annealing dilakukan pada suhu 850°C dan ditahan selama 8 jam. Berdasarkan pengujian I-V meter, film tipis memiliki karakteristik dioda dan responsif terhadap perubahan intensitas iradiasi cahaya. Peningkatan intensitas iradiasi cahaya menyebabkan nilai arus saturasi meningkat namun nilai potensial penghalang menurun. Mobilitas elektron Barium Titanat pada konsentrasi pendadah Ferium 0%, 0,5%, dan 1% didapatkan berturut-turut 2,02×10-6cm2/Vs, 3,16×10-6cm2/Vs, dan 3,03×10-6cm2/Vs. Hasil sifat listrik ini menunjukkan bahwa film tipis BaTiO3 didadah Fe berpotensi sebagai sensor cahaya., The development of technology, especially in electronics, is actively pursued to create innovative devices that are small in size yet deliver maximum performance, such as thin films. Ferium-doped Barium Titanate (BaTiO3) thin films with varying dopant concentrations (0%, 0,5%, and 1%) have been successfully fabricated. The sample solution was filtered using a PVDF filter and then deposited on p-type silicon (100) substrates using the chemical solution deposition (CSD) method with spin coating technique at a spin speed of 3000 rpm for 60 seconds. The annealing process was performed at a temperature of 850°C and held for 8 hours. Based on I-V meter testing, the thin films exhibited diode characteristics and were responsive to changes in light irradiation intensity. Increasing the intensity of light irradiation resulted in an increase in saturation current while the barrier potential decreased. The electron mobility of Barium Titanate with Ferium dopant concentrations of 0%, 0,5%, and 1% were found to be 2,02×10-6cm2/Vs, 3,16×10-6 cm2/Vs, and 3,03×10-6cm2/Vs, respectively. These electrical properties indicate that Fe-doped BaTiO3 thin films have the potential to be used as light sensors.
Keyword: Barium Titanate, CSD, Dopant, I-V meter, Thin films

Judul: Synthesis and Characterizations of Barium Titanate (BaTiO3) Thin Film with Varied Concentration of Iron (II) Acetate (Fe(CH3COO)2) as Dopant
Abstrak: Sintesis film tipis BaTiO3 dengan variasi konsentrasi pendadah Fe (0%; 2%; 4%; dan 6%) menggunakan metode chemical solution deposition (CSD) berhasil dilakukan. Larutan sampel dideposisikan di atas substrat silikon (100) tipe-p dengan teknik spin coating pada kecepatan anguler 8000 rpm selama 60 detik. Proses annealing dimulai pada suhu kamar hingga mencapai suhu 850°C dan ditahan selama 8 jam dengan kelajuan suhu sebesar 1,67°C/menit, dilanjutkan dengan pendinginan hingga suhu kamar selama 12 jam. Ketebalan film dihitung dengan metode volumetrik dan hasilnya berturut-turut yaitu 3,9867 μm; 3,8759 μm; 3,6913 μm; dan 3,0454 μm. Analisis dengan persamaan Cramer-Cohen menghasilkan parameter kisi a = b yaitu 3,843 Å; 3,882 Å; 3,898 Å; dan 3,909 Å serta parameter kisi c yaitu 4,002 Å; 3,938 Å; 4,070 Å; dan 4,024 Å dengan struktur kristal tetragonal. Nilai enegi band gap hasil analisis dengan fungsi Kubelka Munk untuk indirect transition berada dalam rentang 3,0689 – 3,2051 eV dan direct transition berada dalam rentang 2,7660 – 3,0417 eV., The synthesis of BaTiO3 thin film with variations in concentration of Fe as dopant (0%; 2%; 4%; and 6%) using chemical solution deposition (CSD) method has been successfully done. The solutions was deposited on p-type silicon (100) substrates with spin coating technique at the angular speed of 8000 rpm for 60 seconds. The annealing process was started at room temperature until 850°C and was held for 8 hours with a temperature speed of 1.67°C/minutes, followed by cooling process to room temperature for 12 hours. Film thickness was calculated using volumetric method and the results are 3.9867 μm; 3.8759 μm; 3.6913 μm; and 3.0454 μm. The results of the analysis using Cramer-Cohen equation obtained that the lattice parameters a = b are 3.843 Å; 3.882 Å; 3.898 Å; and 3.909 Å and c are 4.002 Å; 3.938 Å; 4.070 Å; and 4.024 Å with tetragonal crystal structure. The values of band gap energy that was analyzed using Kubelka-Munk method equation are in range of 3.0689 – 3.2051 eV for indirect transition and 2.7660 – 3.0417 eV for direct transition.
Keyword: thin film, barium titanate, cramer-cohen, kubelka-munk, dopant

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
Keyword: