philipp_1966#

H. R. Philipp, “Optical transitions in crystalline and fused quartz”, Solid State Commun. 4, 73 (1966)

Source record · Catalogue · Review register

Source kind: measurement

Recorded technique: Reflectance of non-polarized light at near-normal incidence, 8-26 eV, on a Z-cut alpha-quartz crystal, compared with fused silica; below about 7 eV the reflectance was computed from index-of-refraction data (footnote 2: the American Institute of Physics Handbook, 2nd ed., p. 24). Kramers-Kronig analysis (Philipp and Taft, Phys. Rev. 136, A1445 (1964)) of the crystal’s reflectance for eps_1 and eps_2 (p. 73).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes#

Journal pages 73-75 = pdf pages 1-3 (a two-page note; p. 75 is references 3-10 and the German abstract). The library has no extracted tables and the note has none: the pages were read from the page images (2026-09-27). Identity checked against the first page. NOTHING IS TRANSCRIBED: the optical data are in figures only, and the note prints no peak energies, band gap or eps values at the peaks.

WHAT THE NOTE HOLDS (figures, not digitised): - Fig. 1 (p. 73): reflectance (per cent, 0-30) against photon energy (0-26 eV) of crystalline quartz (‘SiO2 (crystal)’) and fused quartz (‘SiO2 (fused)’); ‘For clarity, the values for fused quartz have been lowered by 5 per cent’ (caption). The curves show ‘a series of relatively sharp peaks which are slightly broadened for the amorphous material’ (p. 73). - Fig. 2 (p. 74): eps_1 and eps_2 of crystalline quartz on a logarithmic axis (0.1-10) against photon energy (0-20 eV), from the Kramers-Kronig analysis; ‘The curves for fused SiO2 are very similar and for reasons of clarity are not shown here’ (p. 73).

TEXT (no vocabulary quantity; notes only): - The spectrum can be represented ‘by a series of four oscillators, which become lifetime broadened as one goes to higher energies, followed above ~20 eV by a region of relatively smooth absorption possibly associated with transitions from the deeper lying L-shell electrons of oxygen’ (p. 73); the oscillator energies are not given. - Both forms ‘become opaque’ above about 8 eV (p. 73): a qualitative statement, not a band-gap determination. - Eqs. (1)-(2) (p. 74): the classical oscillator polarizability, eps_1(omega) - 1 = 4 pi alpha = 4 pi rho (sum_j f_j e^2/(4 pi^2 m) (omega_j^2 - omega^2)/((omega_j^2 - omega^2)^2 + Gamma^2 omega^2) + A), with f_j the oscillators per unit mass and rho A the core contribution; the local-field correction is neglected (footnote 6). No parameters are given, so it is not recorded as a formula. - ‘The density ratio 2.65/2.20 = 1.2 of crystalline compared to fused quartz’; [eps_1(omega) - 1]/rho at hbar omega = 2 eV is 0.52 (crystalline) and 0.51 (fused) (units not printed; cm^3/g with the densities in g/cm^3), and (alpha/rho)_crystal / (alpha/rho)_fused = 1.02 ‘throughout most of the transparent range’ (p. 74). These come, presumably, from the handbook index data of footnote 2, not from new measurements. (With rho = 2.65, 0.52 gives eps_1 = 2.38, n = 1.542, the ordinary index of quartz near 620 nm; with 2.20, 0.51 gives n = 1.457, fused silica’s.) - The Si-O distance, about 1.62 A (p. 74, from Wyckoff).

LATER USE. Philipp’s J. Phys. Chem. Solids 32, 1935 (1971) (philipp_1971) shows the same reflectance (its Fig. 1, same caption and offset) with the Kramers-Kronig results of both forms; Palik’s handbook chapter (philipp_1985, Table X, tags [9] and [9, 10]) is the first tabulation of these results, and cites this note. Lamy (lamy_1977) finds Philipp’s fused-quartz peaks narrower than his own, especially near 1220 A (10.2 eV), his crystal-quartz reflectance in good agreement, and his own crystal eps_1 larger by typically 0.2 than Fig. 2’s. Rife and Osantowski (rife_1980) cite it for the 720 A peak.

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets#

No datasets are recorded.

Formulas#

No formulas are recorded.

Corrections#

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.