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We report on a study of thin (500–4000 Å) and ultrathin (100–500 Å) yttrium–iron–garnet (YIG) films deposited onto amorphous quartz substrates by the pulsed laser deposition technique. The growth conditions of well-formed polycrystalline films have been determined. The crystalline structure and the magnetic behavior of the films are strongly influenced by the processes occurring on the film–substrate interface. Primarily, a strain due to the difference in thermal expansion coefficients of the film and substrate induces a uniaxial anisotropy. Another source of strain are lattice distortions due to oxygen vacancies. The results obtained from x-ray diffraction analysis, magneto-optical, superconducting quantum interference device, vibrating sample magnetometer, and ferromagnetic resonance (FMR) measurements indicate that films thicker than 200 Å can be approximated by a two-layer model. One of the layers with a highly distorted structure and low magnetization is located near the surface. The other one, the upper layer, can be estimated as an almost perfectly formed YIG. Their relative thickness determines the magnetic and FMR behavior of the samples. An equilibrium direction of the magnetization along the film normal has been found to occur in the ultrathin films with the lowest magnetization where the perpendicular anisotropy energy exceeds the dipolar energy.

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Thin magnetic layers have been prepared by pulsed-laser deposition from targets of the orthoferrites: DyFeO3, GdFeO3, SmFeO3, and YFeO3. All layers were deposited onto quartz substrates at a temperature of 450 °C under high-vacuum conditions, i.e., in the absence of additional oxygen. The as-grown films show evidence of the following phases: RFeO3, R3Fe5O12, Fe3O4, and R2O3, where R=Dy, Gd, Sm, and Y. The magnetic properties of these films have been investigated using superconducting quantum interference device magnetometry and magneto-optic (Faraday rotation) measurements taken before and after annealing. These studies reveal that the orthoferrite phase is almost completely (>90%) recovered after an annealing treatment at 860 °C for 1 h. We also report on the temperature dependence of the Faraday rotation for these orthoferrites in the temperature range 25–250 °C.