Highly transparent ceramics of Nd³⁺:Y₂O₃ is reported to be synthesized, with 6 mol % ZrO₂, 25 mol % Sc₂O₃ or Lu₂O₃ added for disordering of the crystal structure. Nanopowders with an average particle size of 12-15 nm were used as starting materials. Nanopowder compaction was performed by the method of uniaxial static pressing combined with ultrasonic action on nanopowders. Compacting pressure was 200 MPa and the ultrasonic generator capacity was 1.5 kW. Pore content and crystallite size have been shown to decrease as yttrium is substituted with isovalent ions of scandium and lutetium and heterovalent ions of  zirconium.

New optical materials with compositions {Nd³⁺:(Lu_0.25Y_0.75)₂O₃+6  mol%ZrO₂}, {Nd³⁺:(Sc_0.25Y_0.75)₂O₃+6mol%ZrO₂}, and {Yb³⁺:(Sc_0.25Y_0.75)₂O₃+6mol%ZrO₂} have been synthesized (Fig. 1), which have a disordered crystal structure. In such ceramics, a transmittance of 82.2 % is obtained at a thickness of 2.5 mm (Fig. 2). It is demonstrated that the disordering of the crystal structure results in the broadening of the ⁴F_3/2→⁴I_11/2 spectral band of Nd³⁺ ions from 11 to 40 nm (Fig. 3). Creation of these materials is important for the development of femtosecond lasers, with the lasing duration inversely proportional to the width of the transition.