Endi Suhendi

Pemodelan Dan Simulasi Microring Resonator Dengan Variasi Kopling Sebagai Sensor Dan Perangkat Telekomunikasi

Untuk memperluas dan menghasilkan kualitas sensor yang baik dari Microring Resonator salah satu objek yang dapat divariasikan ialah kopling dalam devais Microring Resonator . Variasi kopling yang gunakan 0.25, 0.3, 0.5, 0.7. untuk luas sensing dapat dilihat pada FSR ( Free Spectral Range ) dan kualitas sensor dapat dilihat pada FWHM ( full width half maksimum ) sebagai parameter sensor dan perangkat telekomunikasi. FSR tidak dipengaruhi oleh kopling hanya dipengaruhi oleh jari-jari dan panjang gelombang. Dengan panjang gelombang yang digunakan 1300 dan 1350. FSR terbesar didapat pada nilai 1350. Kualitas sensor yang kita lihat pada FWHM. FWHM terbesar didapat pada 1350 (panjang gelombang) dan 0.7 lebar koplingnya. In order to improve the performace of microring resonator, the object that can be varied is the coupler in the microring resonator device. The values of the coupler that varied is 0.25, 0.3, 0.5 and 0.7 in nanometer. For the sensing range of the device can be observed in the FSR (Free Spectral Range) and the sensor quality can be observed in FWHM (full width half maximum) as the sensors parameter and communication device. The FSR was not affected by the coupler but by the radius and the wavelength. In this paper the wavelength that is used are 1300 and 1350. The highest FSR obtained at the 1350 wavelength. The sensor quality is at best when the coupler is 0.7 nm with 1350 wavelength.

Characteristics of a thick film ethanol gas sensor made of mechanically treated LaFeO3 powder

In this work, fabrication of LaFeO3 thick film ceramics for ethanol gas sensor made of mechanically treated (milling) powder was studied. The thick films were fabricated using screen printing technique from LaFeO3 powder treated by HEM (High Energy Milling). The films were baked at 800°C for one hour and analyzed using XRD and SEM. Sensitivity of the films was studied by measuring resistance of them at various temperatures in a chamber containing air with and without ethanol gas. Data of XRD showed that the thick film crystalizes in orthorombic structure with space group of Pn*a. SEM data showed that the films consisted of small grains with grain size of about 225u2005nm. According to the electrical data, the LaFeO3 thick films that produced in this work could be applied as ethanol gas with operating temperature of about 275°C.

Effect of Si interface surface roughness to the tunneling current of the Si/Si1-xGex/Si heterojunction bipolar transistor

In this work we discuss the surface roughness of Si interface impact to the tunneling current of the Si/Si1-xGex/Si heterojunction bipolar transistor. The Si interface surface roughness can be analyzed from electrical characteristics through the transversal electron velocity obtained as fitting parameter factor. The results showed that surface roughness increase as Ge content of virtual substrate increase This model can be used to investigate the effect of Ge content of the virtual substrate to the interface surface condition through current-voltage characteristic.

PENGARUH WAKTU POSTSINTERING HEAT TREATMENT (PHT) PADA KONDUKTIVITAS IONIK ELEKTROLIT PADAT CALCIA STABILIZED ZIRCONIA (CSZ) YANG MENGANDUNG SILICA (SiO2) DAN MAGNESIA (MgO)

PENGARUH WAKTU POSTSINTERING HEAT TREATMENT (PHT) PADA KONDUKTIVITAS IONIK ELEKTROLIT PADAT CALCIA STABILIZED ZIRCONIA (CSZ) YANG MENGANDUNG SILICA (SiO 2 ) DAN MAGNESIA (MgO) . Pengaruh waktu Postsintering Heat Treatment (PHT) pada konduktivitas ionik elektrolit padat CSZ yang mengandung SiO 2 dan MgO telah diteliti. PHT dilakukan dengan tujuan untuk meningkatkan konduktivitas ionik elektrolit padat CSZ yang mengandung SiO 2 dan MgO. Elektrolit padat CSZ yang mengandung SiO 2 dan MgO dibuat menggunakan metode pressing dengan komposisi CSZ, SiO 2 , dan MgO berturut-turut 99 %berat, 0,5 %berat, dan 0,5 %berat. Pelet kemudian disinter pada suhu 1450ᵒC selama 4 jam dan PHT pada suhu 1350ᵒC dengan variasi waktu 0 jam, 4 jam, dan 8 jam. Analisis struktur kristal menunjukkan bahwa pelet yang telah dibuat membentuk kristal kubik dan tidak terpengaruh PHT. Analisis densitas menunjukkan bahwa terjadi peningkatan densitas seiring peningkatan waktu PHT tetapi peningkatan tersebut tidak begitu signifikan. Analisis struktur mikro menunjukkan bahwa tidak terdapat perbedaan ukuran butir yang signifikan seiring peningkatan waktu PHT, namun terjadi perubahan distribusi pori. Berdasarkan penelitian yang telah dilakukan diketahui bahwa seiring peningkatan waktu PHT terjadi pula peningkatan konduktivitas ionik elektrolit padat CSZ yang mengandung SiO 2 dan MgO.

EFFECT OF ADDITION OF GADOLINIA DOPED CERIA ON THEELECTRICAL PROPERTIES OF LANTHANUM STRONTIUM MANGANITE-YTTRIA STABILIZED ZIRCONIA FOR SOLID OXIDE FUELCELL CATHODE

A research on the effect of adding Gadolinia Doped Ceria (GDC) on the electrical property, in this case is the electronic conductivity of thick film ceramic of Lanthanum Strontium Manganite- Yttria Stabilized Zirconia (LSM-YSZ) used as an Solid Oxide Fuel Cell (SOFC) cathode has been done. Thick film cathode was coated by screen printing method. Compositions for the cathodes were 50 : 50 : 0; 50 : 40 : 10 and 50 : 30 : 20 for LSM, YSZ, and GDC, respectively. X-Ray Diffractometer (XRD) analysis showed that after the addition of GDC, it was known that there were three main phases in the thick film ceramic cathode i.e. LSM, YSZ, and GDC. Moreover, there was a second phase in each composition of thick film ceramic cathode of SrZrO 3 . Scanning Electron Microscope (SEM) analysis showed that the number of pores and grain size of the LSM part increased qualitatively with increasing concentration of the GDC. Moreover, the electronic conductivity measurement using the Four Point Probe Technique showed that the addition of GDC also increased the electronic conductivity from 0.00406 S/cm to 1.082 S/cm at temperature of 600 o C. Keywords: Cathode, LSM, YSZ, GDC, SOFC

SYNTHESIS OF THICK FILM Fe 2 O 3 -NiO CERAMICS USING LOCAL Fe 2 O 3 FOR ACETONE GAS SENSOR

In order to get self capability in gas sensor especially acetone gas sensor by utilization of local material, thick film Fe 2 O 3 -NiO ceramics have been fabricated using local Fe 2 O 3 as raw material. Powder of Fe 2 O 3 has been processed from mineral by dissolution and precipitation. The derived powder was mixed with NiO powder homogeneously with composition of 50-50 in mole %. The mixed powder was then mixed with Organic Vehicle (OV) made of alpha terpineol and ethyl cellulose with composition of 75 weight % mixed powder and 25 weight % OV forming a paste. The paste was coated on alumina substrates by screen printing method, then fired at 1000 °C for 90 minutes to get thick film ceramics. The thick film was analyzed using X-RayDiffraction (XRD). The film was subjected to Scanning Electron Microscope (SEM) analyses. Resistance of the thick films was masured at different temperatures in air and acetone gas atmosphere. Analyses of XRD showed that the produced ceramic has phase of NiFe 2 O 4 ,. Data of SEM showed that the ceramic has small grain and high porosity. Electrical data showed that the ceramic was sensitive to acetone gas. Keywords: Thick film, Gas sensor, Acetone, Fe 2 O 3 , NiO, NiFe 2 O 4 .