Nano metal compound particles, coating material and film using the same, method for producing film, and method of producing nano metal compound particles

Nano metal compound particles having an average particle size of 50 nm or less, a maximum particle size of 100 nm or less, and a peak ωt of 2.8 eV or less, the peak cot corresponding to a resonant frequency of an oscillator according to a spectroscopic ellipsometry method for a batch of nano metal compound particles with a film thickness in a range of 50 nm to 200 nm fitted to a Lorentz model using a theoretical equation shown below:

• ε(ω)=ε∞+fωt2/ωt2+ω2+iγ0ε
• wherein ω denotes a frequency of incident light, ωt denotes the oscillator center of the oscillator, γ0 denotes a damping factor, f denotes an oscillator strength, ε(ω) denotes a permittivity function, ε∞ denotes a limit value of high-frequency permittivity function, and i is an imaginary number.