LaAl_11.76-x-y(Ni_xTi_y)O₁₉ (x,y=0.2-0.8) microwave dielectric ceramics exhibit τ_f nearly zero

Abstract The development of mobile communication technology urgently needs microwave dielectric ceramic materials with high-temperature stability. Herein, LaAl 11.76-x-y (Ni x Ti y )O 19 (LANT, x,y =0.2-0.8) ceramic samples were produced using the solid-state reaction technique. The experimental results show that after sintering at 1300 °C for 2 h, the excellent microwave dielectric properties are gained at x =0.4 and y =0.6, ε r =18.1, Q×f=23677 GHz, and τ f =+0.15 ppm/°C. The ε r and Q×f values first rise and then diminish as the amount increases x due to the change in the structural stability of the material and the symmetric tensile pattern of the Al/NiTi-O bond. It is speculated that the addition of [Ni x Ti y ] 3+ increases the inclination angle of the Oxygen octahedron, and thus promotes the orientation of τ f to zero. This work verifies the great potential of LANT ( x,y =0.2-0.8) ceramics in improving the temperature stability of microwave devices.