a Crystal field spectra arise from short range order (e.g. nearest neighbors) and so can be used to probe the structure of glasses as well as crystals. Below are sketched spectra of Ti3+ (one d electron) in an alkali silicate glass and an aluminum-rich silicate glass. a. Calculate Dq for each host in eV. Recall that the energy of a photon is hc/wavelength, where h is Planck's constant, and c is the speed of light. Thus, 1 eV = 8065.54 cm-1. b. Explain why Ti3+ produces an absorption in the visible frequency range. c. What are the relative sizes of the Ti3+ sites in the glasses (i.e. which is bigger and which is smaller)? Explain your reasoning. = 3+ 20,300 cm-1 22,400 cm-1 Absorbance Alkali silicate glass Aluminosilicate glass Wavenumber a Crystal field spectra arise from short range order (e.g. nearest neighbors) and so can be used to probe the structure of glasses as well as crystals. Below are sketched spectra of Ti3+ (one d electron) in an alkali silicate glass and an aluminum-rich silicate glass. a. Calculate Dq for each host in eV. Recall that the energy of a photon is hc/wavelength, where h is Planck's constant, and c is the speed of light. Thus, 1 eV = 8065.54 cm-1. b. Explain why Ti3+ produces an absorption in the visible frequency range. c. What are the relative sizes of the Ti3+ sites in the glasses (i.e. which is bigger and which is smaller)? Explain your reasoning. = 3+ 20,300 cm-1 22,400 cm-1 Absorbance Alkali silicate glass Aluminosilicate glass Wavenumber