Judul: Sintesis dan Karakterisasi Film BiFeO3 didadah Barium (II) Asetat (Ba(CH3COO)2).
Abstrak: Sintesis film BiFeO3 dengan pendadah Barium (II) Asetat (Ba(CH3COO)2), variasi konsentrasi pendadah yang digunakan 0%; 0,5%; 1%; dan 1,5% diatas substrat Si (100) tipe-p dibuat dengan metode chemical solution deposition (CSD) dengan teknik spin coating telah berhasil dilakukan. Proses annealing dimulai dari suhu ruang kemudian dinaikan hingga suhu annealing 850oC dengan kenaikan suhu 1.67oC/menit dan ditahan konstan selama 8 jam pada suhu annealing tersebut. Selanjtnya dilakukan proses pendinginan sampai kembali pada suhu kamar selama 12 jam. Menghitung ketebalan film yang dihasilkan dengan menggunakan metode volumetrik, ketebalan yang dihasilkan yaitu 1,667 μm, 1,9047 μm, 2,1164 μm, dan 2,3809 μm. Analisis data XRD dengan metode Cramer-Cohen menghasilkan nilai parameter kisi a=b sebesar 5,4247 Å, 5,4326 Å, 5,4993 Å, dan 5,5691 Å. Serta parameter kisi c yaitu 14,1241 Å, 14,1533 Å, 14,3525 Å, dan 14,5720 Å, dengan struktur kristal heksagonal. Nilai energi bandgap yang dihasilkan dari analisis dengan fungsi Kubelka Munk untuk indirect transition berada pada kisaran 2,6246 – 2,5751 eV., Synthesis of BiFeO3 film with Barium (II) Acetate (Ba(CH3COO)2), the concentration variation of the solvent used are 0%; 0.5%; 1%; and 1.5% above the p-type Si (100) substrate that are made by chemical solution deposition (CSD) method with spin coating technique has been successfully carried out. The annealing process is started from room temperature, it is increased to 850oC of annealing temperature with 1.67oC/minutes of temperature increase. It is constantly held for 8 hours at the annealing temperature. After that, the cooling process is carried out until the temperature returns to room temperature for 12 hours. The results of thickness film are calculated using the volumetric method, including 1.667 m, 1.9047 m, 2.1164 m, and 2.3809 m. The results of XRD data analysis is lattice parameter values a=b, which is using the Cramer-Cohen method; they are 5.4247, 5.4326, 5.4993, and 5.5691. In addition, for lattice parameters c with a hexagonal crystal structure are 14.1241, 14.1533, 14.3525, and 14.5720. The results of band gap energy values, which is using the Kubelka Munk function for indirect transitions, ranged from 2.6246 – 2.5751 eV.
Keyword: BiFeO3, CSD, Spin Coating, lattice parameters, band gap energy

Judul: Pembuatan Fim Tipis BiFeO3 didadah Cerium Oksida (CeO2)
Abstrak: Film BiFeO3 dengan beberapa persentase pendadah cerium oksida (0%, 2%, 4%, 6%) dengan menggunakan metode chemical solution deposition (CSD). Selain itu, menggunakan teknik spin coating dengan kecepatan putar 8000 rpm telah berhasil dibuat diatas subtrat silikon tipe-p 100. Suhu yang digunakan pada saat proses anealing sebesar 850 oC dan ditahan selama 8 jam dengan kelajuan suhu sebesar 1,67 OC/menit, lalu mengikuti proses pendinginan hingga suhu kamar selama 13 jam. Film BiFeO3 yang didadah dengan pendadah cerium oksida (0%, 2%, 4%, 6%) memiliki nilai energi bandgap secara langsung sebesar 2,7650 eV; 2,7073 eV; 2,6556 eV; dan 2,6303 eV. Nilai energi bandgap secara tidak langsung sebesar 2,5151 eV; 2,4874 eV; 2,4664 eV; dan 2,4539 eV. Hasil parameter kisi a dan c yang didapatkan pada karakterisasi XRD sebesar 5,5829 Å; 5,6470 Å; 5,6883 Å; 5,7041 Å dan 14,2152 Å, 14,3222 Å; 14,3839 Å; 14,9271 Å dengan struktur kristal berbentuk heksagonal. Hasil analisis menggunakan perangkat lunak MAUD sebagai data pembanding mendapatkan parameter kisi a dan c sebesar 5,6986 Å, 5,5746 Å; 6,0561 Å; 7,1561 Å dan 13,0074 Å; 13,9398 Å; 13,8179 Å; 14,0931 Å. Analisis hasil menggunakan perangkat lunak MAUD dapat diperoleh visualisasi struktur kristal heksagonal pada film BiFeO3. Kata kunci: BiFeO3, cerium oksida, CSD, energi bandgap, heksagonal., BiFeO3 film with some percentage of ferium concentration (0%, 2%, 4%, 6%) using the CSD method. In addition, using the spin coating technique with a rotational speed of 8000 rpm has been successfully made above 100 p-type silicon substrate. The temperature used during the anealing process was 850 oC for 8 hours with a temperature speed of 1,67 OC/minute, then followed the cooling process to room temperature for 13 hours. The BiFeO3 film made with ferrium-doped variation concetration (0%, 2%, 4%, 6%) had a direct bandgap energy value of 2,7650 eV; 2,7073 eV; 2,6556 eV, and 2,6303 eV. The bandgap energy value indirect is 2,5151 eV; 2.4874 eV; 2.4664 eV; and 2.4539 eV. The results of the lattice parameters a and c obtained based on XRD characterization are 5,5829 Å; 5,6470 Å; 5,6883 Å; 5,7041 Å and 14,2152 Å, 14,3222 Å; 14,3839 Å; 14,9271 Å with possible hexagonal shape changes. The results of the analysis using the MAUD software as comparison data obtained lattice parameters a and c of 5.6986 , 5.5746 ; 6.0561 ; 7.1561 and 13.0074 ; 13.9398 ; 13.8179 ; 14.0931 . Analysis of the results using MAUD software can be obtained visualization of the hexagonal crystal structure on the BiFeO3 film. Keywords: BiFeO3, cerium oxide, CSD, bandgap energy, hexagones.
Keyword: BiFeO3, Cerium Oksida, CSD, energi bandgap, heksagonal

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.
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