ABSTRAK
Penelitian ini membahas kinetika pertumbuhan kristal dan karakterisasimaterial penyerap gelombang mikro berbahan dasar LSMO di substitusi Fe-Tidengan formula La0.5Sr0.5Mn0.8Fe0.1Ti0.1O3. Preparasi material menggunakanmetode paduan mekanik selama 10 jam, kemudian diberikan variasi waktu 0, 1, 5dan 24 jam pada temperatur 1000 C, 1100 C dan 1300 C. Pengujian XRDsebelum proses sintering dan sesudah sintering yang menunjukan hasil bahwasintesa bahan atau paduan La0.5Sr0.5Mn0.8Fe0.1Ti0.1O3 memiliki fasa tunggal (singlephase) dengan struktur kristal orthorombik dengan parameter kisi a=7.7 Å ; b=5.5Å ; c=5.4 Å. Berdasarkan hasil pengukuran ukuran kristal rata-rata melaluimetode Debye-Scherrer, kinetika pertumbuhan kristal rata-rata mengikutipersamaan Avrami dengan nilai energi aktivasi sebesar Q=21.29 kJ/mol.K.Karakteristik nilai serapan gelombang mikro pada frekuensi 8?15 GHz dianalisamenggunakan Vector Network Analyzer (VNA). Karakterisasi kurva reflektansiloss sampel material T1300-24jam memberikan nilai intensitas yang palingoptimal yaitu sebesar -3.58 dB atau 34% frekuensi serapan pada frekuensi optimal12.5 GHz, dan lebar pita penyerapan sebesar 3 GHz.

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ABSTRACT
The kinetics of crystallite growth and microwave characteristics for Fe-Ti

substituted LSMO with La0.5Sr0.5Mn0.8Fe0.1 Ti0.1O3 composition was investigated.

Material preparation was carried out by means of mechanical alloying process for

10 hours milling times. The powders which prepared from mechanically milled

material were sintered at temperatures 1000 C, 1100 C dan 1300 C respectively

for 0, 1, 5 and 24 hours time sintering time. The XRD traces for sintered materials

confirmed that the La0.5Sr0.5Mn0.8Fe0.1 Ti0.1O3 is a single phase material with a

orthomobic crystal structure a=7.7 Å ; b=5.5 Å ; c=5.4 Å. Refering to mean

crystallite size evaluation which employing Debye Scherrer method. It was found

that the kinetics of mean crystallite growth followed the Avrami equation with an

activation energy for crystallite growth Q=21.29 kJ/mol.K. In addition to

crystallite growth kinetics the absorbtion characteristics of material was evaluated

by a Vector Network Analyzer (VNA) in the electromagnetic frequency range 8-

15GHz. The best absorbtion characteristics was found in the sample code T1300-

24h. This follows that the reflection loss of -3.58 dB or 34% was absorb occurred

at frequency 12.5 GHz was the bandwith 3GHz.