Pengaruh daya transduser dan substitusi parsial ion mn ti pada proses destruksi ultrasonik terhadap pembentukan nanopartikel sro 6fe2 xmnx 2tix 2o3 (x 0 0 1 0) = The effect of transducer power and substitution of mn - ti ions to the formation of sro 6fe2 xmnx 2tix 2o3 (x 0 0 1 0) nanoparticles in ultrasonic destruction process