  Chemical composition is the primary factor that determines the electronic
band structure and thus also influences the optical properties of plasmonic
ceramics including nitrides and oxides. In this work, the optical and plasmonic
properties of TiN, ZrN and their hypothetical intermediate alloys Ti1-xZrxN (x=
0, 0.25, 0.50, 0.75, and 1), are studied by using first-principles density
functional theory. We demonstrate the effects of electronic band structure
tuning (band engineering) on the dielectric properties by varying the
concentration of metallic constituents. Our calculations reveal that bulk
plasma frequency, onset of interband transitions, width of bulk plasmon
resonance and cross-over frequency, can be tuned flexibly in visible spectrum
region by varying the amount of Zr concentration in Ti1-xZrxN alloy system. We
found that low threshold interband energy onset (~1.95 eV) leads to high losses
in Ti rich compounds than that of ZrN which points to lower losses.
