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Thin films with different compositions of Ce-substituted yttrium iron garnet (Ce:YIG (Y 2 CeFe 5 O 12 )), Ga-doped Ce:YIG (Ce:Ga:YIG (Y 2 CeFe 4.25 Ga 0.75 O 12 )), and Gd-doped Ce:YIG (Ce:Gd:YIG (Y 1.6 CeGd 0.4 Fe 5 O 12 )) were deposited on gadolinium gallium garnet (GGG (Gd 3 Ga 5 O 12 )) substrates in O 2 or Ar background gas by pulsed-laser deposition (PLD) technique. Crystalline films were obtained at a lower O 2 gas pressure of 20 mTorr or at higher Ar gas pressures of more than 100 mTorr. In addition, the behavior of YO molecules was visualized by two-dimensional laser-induced fluorescence (2D-LIF), in order to investigate the oxidation dynamics in the ablation plume. The oxidation dynamics and the crystallinity had close correlation.

The magnetooptical properties and magnetic-field-sensing properties of bulk Ce-substituted YIG (Ce x Y 3− x Fe 5 O 12 ) crystals were studied. There was an absorption edge at 1200 nm and a large negative Faraday rotation was obtained. Faraday rotation was increased to a greater extent by Ce substitution than by Bi substitution. The magnetic-field sensitivity of Ce 0.24 Y 2.76 Fe 5 O 12 was 0.0048% m/A which was larger than that of (BiGdLaY) 3 (FeGa) 5 O 12 . The optical current transformer (CT), using a Ce:YIG crystal as a sensor head, could measure the alternating steady state, faulting, breaking and reclosing currents. These results suggest that cerium-substituted yttrium iron garnet is a high-performance material suitable for magnetic-field (or electric-current) sensors.

Bi-doped yttrium iron garnet (Bi x Y 3− x Fe 5 O 12 , Bi:YIG) thin films, which can be used as electric current sensors, are grown on Gd 3 Ga 5 O 12 (GGG) substrates by pulsed laser deposition (PLD) using an ArF excimer laser. The growth condition for high quality epitaxial Bi:YIG thin films is investigated by varying the PLD process parameters, such as the substrate temperature and ambient oxygen gas pressure. The epitaxial film growth is attained at the substrate temperature of around 500 °C and at ambient oxygen pressure between 125 and 175 mTorr. The optical properties of epitaxial films are measured and the maximum magneto-optic sensitivity coefficient is observed to be 44.1°/T with a film thickness of about 0.7 μm at a wavelength of 500 nm. The results indicate that the PLD technique can be useful for realizing a miniature current sensing device with the Bi:YIG thin film.

The linear magnetic birefringence (LMB) in Ce-substituted Y3Fe5O12 crystals grown by the floating zone method and its influence on the characteristics of optical magnetic field sensors were studied. It was found that the measured LMB values of Δn001=-1.2×10-4 and Δn111=-1.7×10-4 in the Ce0.17Y2.83Fe5O12 sample were three times as large as those in YIG. The influence of LMB on the linearity of the magnetic field sensor, which was based on the Faraday effect created by magnetization rotation, was estimated quantitatively from the analytical result obtained by the Jones matrix calculation method. It was found from both calculation and experimental investigations that LMB strongly affects the linearity of the sensor output. It was successfully demonstrated that use of a pair of Ce:YIG crystals was very effective in improving the sensitivity of the sensor output.

We describe the deposition and characterization of Bi12SiO20 (bismuth silicon oxide; BSO) thin films on Y-stabilized zirconia (YSZ) and SiO2 glass substrates by pulsed-laser deposition (PLD) for the application of an electric field sensor. It was found that all films deposited on YSZ substrates heated at 400 °C and more were crystallized and the (310) plane was perpendicular to the substrate normal. The highly (310) oriented crystallized films were even deposited on SiO2 glass substrates, and this will make it possible to grow the crystallized films on the end surface of a SiO2 glass fiber.

We described the pulsed-laser deposition (PLD) and characterization of cerium doped yttrium iron garnet (Ce:YIG, Ce/sub 0.6/Y/sub 2.4/Fe/sub 5/O/sub 12/) thin films for magnetic field sensor applications. It was found that crystallized Ce:YIG films were obtained by the deposition at 900/spl deg/C substrate temperature and in 10 mtorr argon or oxygen ambient gas. The Faraday rotation angle was very large; 4.2 deg//spl mu/m at 430 nm wavelengths. The charge state control of cerium was important for the crystallinity and high Faraday rotation. The lower temperature or higher ambient gas pressure controlled the cerium charge state Ce/sup 4+/, because the oxygen and cerium released from an ablated target accelerated to form cerium oxide, the thin film was noncrystalline and no Faraday rotation occurred.

Ce-doped yttrium iron garnet (Ce:YIG) with different compositions of Y 2 CeFe 5 O 12 , Y 2 CeFe 4.25 Ga 0.75 O 12 , Y 1.6 Gd 0.4 CeFe 5 O 12 were deposited by PLD on GGG(111) SUBSTRATE. The crystallinity, transmittance and surface morphology were observed for the films deposited at different depositions conditions of argon or oxygen gas pressures and substrate temperatures.

Ce-doped yttrium iron garnet (Ce:YIG) thin films were deposited for the first time by pulsed-laser deposition (PLD) on gadolinium gallium garnet (GGG(111)) substrates. Well crystallized film was obtained at high substrate temperature (approximately 900 degree(s)C) and in low Ar gas pressure (approximately 50 mtorr). A Faraday rotation angle was wavelength dependent, and the largest value was 4.2 x 104 deg/cm at 420 nm. The control of the charge state of Ce ion is necessary for crystallization. The deposited Ce:YIG films were transferred by laser-induced forward transfer (LIFT) process to obtain a thick film.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We describe the pulsed-laser deposition (PLD) and characterization of bismuth silicon oxide (BSO, Bii2SiO2o) thin films and Ce-doped yttrium iron garnet (Ce:YIG, CeY3_Fe5Oi2) thin films for the electric and magnetic fieldsensor application. It was found that BSO films deposited on yttria-stabilized zirconia (YSZ) substrates heated at 400 °C or higher in an oxygen ambient gas were crystallized and the (310) plane was perpendicular to the substratenormal. The highly (310) oriented crystallized films were also deposited even on Si02 glass substrates. On the otherhand, crystallized Ce:YIG films were obtained by the deposition in an Ar ambient gas, and not in an oxygen ambientgas, indicating the importance of the control of the charge state of Ce ions. The magneto-optic data of Ce:YIG films are also reported.Keywords: laser ablation, PLD, electric sensor, magnetic sensor, BSO, Ce:YIG 1. INTRODUCTION Electro- and magneto-optic crystals have been used for the electric field and magnetic field sensors.1'2 In these

Pulsed laser deposition (PLD) technique is applied for fabricating Bi doped yttrium iron garnet (BixY3-xFe5O12) (Bi:YIG) thin films which can be used for optical current transformer. Growth conditions of high quality Bi:YIG thin films on Gd3Ga5O12 (GGG) substrates are investigated by varying PLD process parameters. The magneto-optic sensitivity coefficient of the fabricated Bi-YIG thin film is measured as 44 deg/T at a wavelength of 500 nm.

Pulsed-laser deposition (PLD) growth of stoichiometric LiNbO3 has been investigated in detail in the low gas pressure region where the mean free path of ablated species is longer than the target-to-substrate distance. We have found that the reduction of gas pressure effectively suppresses Li deficiency, and therefore, is a promising way of overcoming the nonstoichiometory problem that has been inherent to the conventional PLD growth of LiNbO3. In such low-pressure growth, we have found that ozone atmosphere is more favorable than that of molecular oxygen, because the crystallographic quality and surface flatness is better in films grown with ozone than in those grown with molecular oxygen. These results open the way to nanoscale lattice engineering of Li-containing oxide materials.

A cerium-substituted yttrium iron garnet (Y3-x Ce x Fe5O12) single crystal was grown by the traveling solvent floating zone (TSFZ) method in an oxygen environment. Using a Fe- and Ce-rich solvent, high quality single crystals with smooth and lustrous surface were grown at a rate of 1.0 mm/h. The segregation coefficient of Ce was calculated approximately as 0.2 from the compositional profile in the grown crystals measured by electron probe X-ray microanalyzer (EPMA). The optical absorption coefficient and the Faraday rotation angle of Y2.82Ce0.18Fe5O12 at 1550 nm wavelength were 0.12 cm-1 and -740 deg/cm, respectively. The figure of merit of a Faraday rotator was 1423 deg/dB. The absorption loss and sensitivity of the same Y2.82Ce0.18Fe5O12 (d=0.6 mm) for the magnetic field sensor were 0.03 dB and 0.1%/Oe, respectively, at 1550 nm wavelength. These results suggest that cerium-substituted yttrium iron garnet is a high performance material for the Faraday rotator at 1550 nm wavelength.

Derivatives of tenuazonic acid, 3-acetyl-5-sec-butyltetramic acid, were synthesized. 5-Substituted 3-acetyl tetramic acids were condensed with primary aromatic amines refluxing in alcohol. The structure of the condensation products were determined as 5-substituted 3-(1'-anilinoethylidene) pyrrolidine-2, 4-dione. The stability of the one of the condensation products was investigated, and it was found to be stable in acidic and neutral, but unstable in alkaline medium.