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This study aims to determine the microstructure, morphology, and dielectric properties of Ba1-xLaxTiO3 modified with variations moles concentration of 10% and 15% Lanthanum at sintering temperatures of 1300°C and 1400°C for 4 hours. Ba1-xLaxTiO3 was synthesized using the co-precipitation method. The results of characterization using X-Ray Diffraction (XRD) showed that the greater concentration of La mole caused a diffraction angle shift to the right. The crystallite size decrease asthe increasing concentration of La mole and sintering temperature. The smallest crystallite size (36.63 nm) belong to a sample of Ba0,85La0,15TiO3 sintered at 1400°C. The intensity and the crystallinity decreased with increasing concentration of La mole. Scanning Electron Microscopy (SEM) photographs showed that grain size got smaller with increasing La mole concentration. The dielectric constant obtained from the results of characterization using a Resistance Inductance Capacitance meter (RLC meter) showed that the higher the concentration of La mole added, the greater the dielectric constant produced. The highest dielectric constant was 414 belonged to the sample Ba0,85La0,15TiO3 sintered at 1400°C.

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Barium Titanate (BT) is one of the most intriguing ferroelectric materials widely exploited both for academic and technological utilization. The study aimed to investigate characteristics of BT ceramics Synthesized by co-precipitation (BT-C) and solid-state methods (BT-S) with variation of sintering temperatures. Here, the sintering temperatures are 900°C, 1000°C, 1100°C, and 1200°C for 4 h of each The characteristics are microstructure, morphology, and dielectric properties evaluated using X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), and Inductance-Capacitance-Resistance (LCR) meter, respectively. As results, the XRD patterns shows a pure perovskite single phase of BT was obtained by solid-state method at sintering temperature of 1000°C. While, the same result was obtained by co-precipitation at sintering temperature of 1100°C. The average crystallite size of BT-C and BT-S ceramics are in close values and getting larger with the higher sintering temperatures. Meanwhile, tetragonality of the BT-C tends to be larger as compared to the BT-S. The morphology results revealed big formed particles agglomeration (>5 μm) of the BT-C ceramics and the densities proportionally increased as the higher temperatures exhibited less porosity of ceramics. Meanwhile, the BT-S grains were visible and agglomerated in a much smaller size with the density values were different as the change of the sintering temperatures. The dielectric permittivity of the BT-C and BT-S ceramics were increased with higher sintering temperature. Further, the BT-C ceramics possessed higher permittivity than the BT-S due to high densities (less porosity) of ceramics. The highest permittivity of 1150 at 40 kHz was achieved by BT-C at 1200°C.

This research motivated by the result of evaluation student's ability in literacy science Keywords : Discovery Learning, Literacy Sains, PISA (Programme International Students Assesment)Abstrak: Penelitian ini dilatar belakangi oleh hasil evaluasi kemampuan litersi sains siswa di Indonesia melalui tes PISA semakin menurun. Kemampuan literasi sains siswa salah satunya dipengaruhi oleh model pembelajaran. Model pembelajaran yang dianggap mampu meningkatkan kemampuan literasi sains siswa adalah model discovery learning, karena model ini memodifikasi antara penemuan dan penyelidikan dalam memecahkan masalah sehingga dapat meningkatkan pemahaman konsep siswa yang dapat diterapkan di lapangan. Penelitian ini bertujuan untuk mengetahui pengaruh model discovery learning pada mata pelajaran IPA Terpadu terhadap penguasaan literasi sains siswa. Desain penelitian yang digunakan adalah Noneequivalent Control Group Desain. Lokasi penelitian adalah SMP Negeri I Tayu pada tanggal 16 sampai 23 Mei 2016. Subjek penelitian adalah siswa dari kelas VII. Sampel terdiri dari dua kelas yang diambil degan teknik cluster random sampling. Metode pengumpulan data menggunakan metode tes yaitu pretest dan postest, angket, dan lembar observasi. Tes yang diberikan menggunakan soal-soal yang diperoleh dari soal PISA 2009. Hasil kemampuan siswa dalam menjawab soal sains PISA pada tahap postest kelas eksperimen dan kelas kontrol mempunyai rata-rata sebesar 60 dan 61,. Berdasarkan analisis tahap akhir dengan menggunakan uji t menyatakan bahwa t hitung