were synthesized by high-energy ball milling of stoichiometric ratios of BaF2 (Alfa Aesar, 99 %) and LaF3 (Thermofischer, 99.99 %) in 50 ml zirconia jars with ten zirconia balls of 10 mm diameter for 12 hrs effective milling time. The milling was conducted for 10 minute intervals at 600 rpm and 20 minute break to let the ball milling jars cool down. The precursors were dried prior to milling for 12 hrs in vacuum at 200 °C.