<![CDATA[Abstract:This study discusses the effect of Yttrium (Y) doping variations on the physical and electromagnetic properties of Barium Hexafere (BaFe??O??) synthesized using the solidstate reaction method. The doping variations used were 0.00; 0.01; 0.03; and 0.05 at%. The calcination process was carried out at 600 °C and sintering at 1200 °C. Characterization was performed using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vector Network Analyzer (VNA). The XRD results showed that all samples had a single phase of BaFe??O?? with a hexagonal structure according to JCPDS No. 84-0757 without secondary phases, with the highest crystallinity at a doping of 0.05 at%. SEM analysis showed an increase in grain density and a decrease in porosity with increasing Y doping. VNA testing showed the best Reflection Loss value of –12.98 dB at a frequency of 8.87 GHz with 71.8% microwave absorption. Yttrium doping of 0.05 at% is the optimal composition for enhancing microwave absorption in Barium Hexafere. Keywords:Barium Hexafere, Yttrium, solid state reaction, XRD, SEM, VNA Abstrak: Penelitian ini membahas pengaruh variasi doping Yttrium (Y) terhadap sifat fisis dan elektromagnetik Barium Heksaferrit (BaFe??O??) yang disintesis menggunakan metode solid state reaction. Variasi doping yang digunakan yaitu 0,00; 0,01; 0,03; dan 0,05 at%. Proses kalsinasi dilakukan pada suhu 600 °C dan sintering pada suhu 1200 °C. Karakterisasi dilakukan menggunakan X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), dan Vector Network Analyzer (VNA). Hasil XRD menunjukkan semua sampel memiliki fasa tunggal BaFe??O?? dengan struktur heksagonal sesuai JCPDS No. 84-0757 tanpa fasa sekunder, dengan kristalinitas tertinggi pada doping 0,05 at%. Analisis SEM menunjukkan peningkatan kerapatan butir dan penurunan porositas seiring bertambahnya doping Y. Uji VNA menunjukkan nilai Reflection Loss terbaik –12,98 dB pada frekuensi 8,87 GHz dengan penyerapan gelombang mikro 71,8%. Doping Yttrium 0,05 at% merupakan komposisi optimal untuk meningkatkan kemampuan penyerapan gelombang mikro pada Barium Heksaferrit. Kata kunci: Barium Heksaferrit, Yttrium, solid state reaction, XRD, SEM, VNA]]>
