PENGARUH VARIASI WAKTU TAHAN SINTER TERHADAP STRUKTUR, MIKROSTRUKTUR, DAN PERMITIVITAS RELATIF PADA KERAMIK Mg(Ti0,96Cr0,04)O3
EFFECT OF SINTER RESISTANCE TIME VARIATION ON STRUCTURE, MICROSTRUCTURE, AND RELATIVE PERMITTIVITY IN CERAMICS Mg(Ti0.96Cr0.04)O3
Keramik MgTiO3 merupakan material fungsional yang diaplikasikan dalam sistem komunikasi gelombang mikro. Pada penelitian ini, serbuk Mg(Ti0,96Cr0,04)O3 (MTC004) disintesis menggunakan metode pencampuran larutan antara larutan MgCl2, 0,96TiCl4, dan 0,04CrCl4 yang dikalsinasi pada suhu 800 C selama 4 jam. Selanjutnya, serbuk kristalin MTC004 dikompaksi pada tekanan 10 MPa hingga menghasilkan pelet berbentuk silinder berdiameter 8 mm. Pelet tersebut disinter pada suhu 1300 C dengan variasi waktu tahan 2, 3, dan 4 jam. Penelitian ini bertujuan melaporkan fabrikasi keramik MTC004 dan karakterisasinya menggunakan XRD, SEM-EDX, densitymeter, dan VNA. Hasil menunjukkan struktur ketiga keramik tersebut terdiri atas fasa utama MgTiO3 disertai fasa impurity TiO2, dan MgO (khusus 3 jam). Peristiwa peningkatan background dan penurunan intensitas puncak difraksi ditemukan pada waktu tahan 2 dan 3 jam yang menyebabkan terjadinya peak broadening. Peak broadening terjadi karena adanya distorsi atom dari posisi setimbangnya sehingga difraksi sinar-X tidak terfokus pada satu arah (diffuse) yang mengindikasikan terjadinya Thermal Diffuse Scattering (TDS). Bertambahnya waktu tahan sinter meningkatkan %berat, %molar, parameter kisi, dan volume sel satuan fasa MgTiO3. Uji SEM memperlihatkan semakin naiknya kepadatan keramik. Hal tersebut berkaitan dengan pengukuran densitas bulk yang mengalami kenaikan, yaitu 2,511 gr.cm-3 (2 jam), 3,021 gr.cm-3 (3 jam), dan 3,058 gr.cm-3 (4 jam). Uji EDX membuktikan ketiga keramik mengandung unsur-unsur yang berasal dari bahan awalnya, yaitu O, Mg, Ti, dan Cr. Kemudian, nilai ɛr rata-rata yang dihasilkan semakin tinggi, yaitu 17,32 - 17,51 (pada frekuensi 2-4 GHz). Berbekal data-data struktur, mikrostruktur, dan ɛr tersebut, ketiga keramik MTC004 menjadi material dielektrik yang potensial untuk aplikasi telekomunikasi.
MgTiO3 ceramic is a functional material applied in microwave communication systems. In this research, Mg(Ti0.96Cr0.04)O3 (MTC004) powder was synthesized using a solution mixing method between MgCl2, 0.96TiCl4, and 0.04CrCl4 solutions which were calcined at a temperature of 800 °C for 4 hours. Next, the MTC004 crystalline powder was compacted at a pressure of 10 MPa to produce cylindrical pellets with a diameter of 8 mm. The pellets were sintered at a temperature of 1300 °C with varying holding times of 2, 3 and 4 hours. This study aims to report the fabrication of MTC004 ceramic and its characterization using XRD, SEM-EDX, density meter, and VNA. The results show that the structure of the three ceramics consists of a main phase of MgTiO3 accompanied by impurity phases of TiO2 and MgO (specifically 3 hours). An increase in the background and a decrease in the intensity of the diffraction peak were found at holding times of 2 and 3 hours which caused peak broadening. Peak broadening occurs due to the distortion of atoms from their equilibrium position so that X-ray diffraction is not focused in one direction (diffuse), which indicates the occurrence of Thermal Diffuse Scattering (TDS). Increasing the sintering holding time increases the weight%, molar%, lattice parameters, and unit cell volume of the MgTiO3 phase. The SEM test shows the increasing density of the ceramic. This is related to the measurement of bulk density which has increased, namely 2.511 gr.cm-3 (2 hours), 3.021 gr.cm-3 (3 hours), and 3.058 gr.cm-3 (4 hours). The EDX test proves that the three ceramics contain elements originating from the original material, namely O, Mg, Ti and Cr. Then, the resulting average ɛr value gets higher, namely 17.32 - 17.51 (at the 2-4 GHz frequency). Armed with these structural, microstructural and ɛr data, the three MTC004 ceramics become potential dielectric materials for telecommunications applications.