Judul: Pengaruh Variasi Konsentasi Pendadah RuO2 Terhadap Struktur Kristal Dan Sifat Optik Dari Film Tipis BaTiO3
Abstrak: Pembuatan film tipis BaTiO3 bertujuan menganalisis sifat optik, struktur morfologi spectra XRD, dan citra SEM-EDAX. Film tipis Barium Titanat (BaTiO3) murni dan BaTiO3 dengan variasi pendadah RuO2 2%, 4%, dan 6% yang ditumbuhkan pada silikon tipe-p (100) dengan metode Chemical Solution Deposition (CSD). Film BaTiO3 dan BaRuTiO5 dibuat dalam konsentrasi 2 M. Film tersebut ditumbuhkan dengan tiga kali pelapisan menggunakan teknik spin coating pada kecepatan putar 6000 rpm, 8000 rpm, dan 10000 rpm selama 30 detik. Film kemudian di annealing pada suhu 850 oC selama 8 jam. Film dikarakterisasi menggunakan spektrofotometer UV-Vis untuk mengetahui sifat optik berupa analisis nilai reflektansi, indeks bias dan energy gap. Metode ini memiliki keunggulan dapat mengontrol stokiometri film tipis dengan kualitas yang baik, prosedur yang mudah dan biaya yang relatif murah. Energi band gap berkisar 3.25 sampai 3.27 eV dengan indeks bias 2.7749894 sampai 2.77498944. Film tipis BaTiO3 memiliki parameter kisi a = 4.035 sampai 4.097 Ǻ dan c = 4.043 sampai 4.107 Ǻ serta ukuran kristal berada pada rentang 0.175 μm sampai 0.5 μm.
Keyword: film tipis, sifat optik, barium titanat, chemical solution deposition, pendadah, ruthenium oksida

Judul: Characteristic of BaTiO3 Thin Films  Electricity Doped with Ruthenium on Type-P Silicone Substrate
Abstrak: Film tipis Barium Titanat (BaTiO3) telah berhasil dibuat dengan menggunakan metode Chemical Solution Deposition (CSD) dan Spin Coating. Dalam penelitian ini telah dibuat film BaTiO3 didadah Ru dengan variasi konsentrasi pendadah 0%, 0,5%, dan 1%. Film tipis tersebut dideposisikan di atas substrat silikon tipe-p (100). Film tipis BaTiO3 melalui tahap annealing pada suhu 850oC ditahan selama 8 jam dengan kelajuan kenaikan suhu sebesar 1,67oC/menit, kemudian mengalami proses pendinginan 12 jam. Film tipis BaTiO3 didadah Ru dikarakterisasi sifat listriknya dengan menggunakan I-V meter, dan Space Charge Limited Current (SCLC). Kurva I-V menunjukkan bahwa film tipis memiliki karakteristik dioda dan responsif terhadap perubahan intensitas radiasi cahaya. Peningkatan konsentrasi pendadah Ru menyebabkan nilai saturasi meningkat, sedangkan nilai potensial penghalang menurun. Penambahan konsentrasi pendadah Ru secara linear menyebabkan kenaikan nilai mobilitas muatan. BaTiO3 didadah Ru memiliki sifat kelistrikan dan responsif terhadap cahaya., Barium Titanate (BaTiO3) thin films have been successfully created using Chemical Solution Deposition (CSD) Method and Spin Coating. In this research, BaTiO3 films are doped with Ru with concentration variants of 0%, 0,5%, and 1%. Those thin films are deposited above a silicon substrate type-p (100). BaTiO3 films are through annealing process at 850°C and held for 8 hours with temperature rise rate of 1,67°C/minutes, then undergoes a cooling process for 12 hours. BaTiO3 doped with Ru were characterized by their electrical properties with I-V Meter, and Space Charge Limited Current (SCLC). The curve from I-V meter shows that thin films have diode characteristics and responsive to change in the intensity of light radiation. The increase of doped concentration of Ru causes the saturation value to also increase, meanwhile the potential value of the barrier decreases. The addition of doped concentration of Ru linearly causes the increase of load mobility. BaTiO3 doped with Ru has electrical properties and is responsive to light.
Keyword: saturation current, BaTiO3, CSD, I-V meter, electron mobility, spin coating, barrier voltage

Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
Keyword: