Josef Buršík

Characterisation of bismuth-doped yttrium iron garnet layers prepared by sol–gel process

Abstract Yttrium iron garnets and Bi-substituted yttrium iron garnets were prepared by two different sol–gel processes. We investigated the evolution with temperature of XRD patterns and of the magnetisation of powders issued from sol–gel solution decomposition. We prepared layers on silica glass by the spin- or dip-coating processes. XRD patterns on layers were also obtained. The dependency of the Faraday effect upon the light wavelength and Bi amount was shown. The main result is the possibility to prepare stable sol–gel solutions containing bismuth, yttrium and iron precursors which lead to garnet phase after annealing at low temperature. These bismuth-doped garnet phases give the expected magneto-optical properties. These processes are promising for the preparation of inexpensive magneto-optical recording media.

Dielectric, magnetic, and lattice dynamics properties of Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22: Comparison of ceramics and single crystals

We prepared multiferroic Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22 ceramics and compared their magnetic and dielectric properties with single crystal. Magnetic susceptibility and microwave resonance measurement revealed magnetic phase transition at TC=312 K, similar as in single crystal. Ferroelectric (FE) phase can be induced by external magnetic field in all investigated samples and the phase diagram in ceramics qualitatively resembles that of the single crystal. The range of magnetic fields, where the FE phase is induced, broadens after annealing of single crystal. Ceramics quenched after sintering exhibit several orders of magnitude lower conductivity than the single crystal. Heavily damped magnetic resonance was discovered in terahertz spectra at 10 K and its frequency softens below 5 GHz near TC. Number and symmetry of observed infrared (IR) and Raman active phonons correspond to paraelectric phase with D3d5 hexagonal structure. No evidence for a structural phase transition was found in the IR and Ram...

Preparation of potassium tantalate thin films through chemical solution deposition

Abstract Potassium tantalate (KT) KTaO 3 thin films of both pyrochlore and perovskite cubic structures were prepared through the chemical solution deposition (CSD). A homogeneous and stable precursor solution was obtained from potassium iso-butoxide and tantalum iso-butoxide in absolute iso-butanol with an additive of diethanolamine as a stabilizer. The effects of K:Ta sol stoichiometry, type of substrate (both amorphous, and single crystal substrates), type of buffer interlayer [Al 2 O 3 , Y-stabilized ZrO 2 (YSZ), PbTiO 3 , PbTiO 3 –Al 2 O 3 composite, KNbO 3 (KN)], and annealing regime on the kinetics of pyrochlore to perovskite transition has been studied. KT perovskite films have been successfully prepared on (100)MgO, and (0001)Al 2 O 3 . Using SiO 2 and Si substrates, perovskite films have been obtained via insertion of Al 2 O 3 and KNbO 3 buffer layers.

Stabilization of the high-spin state of Co3+in LaCo1−xRhxO3

The rhodium doping in the LaCo

Nanocomposites NiFe2O4/SiO2 and CoFe2O4/SiO2-Preparation by Sol-Gel Method and Physical Properties

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Structure and properties of novel cobaltates Ln0.3CoO2 (Ln = La, Pr, and Nd)

Rh

Preparation of Y3Fe5O12/SiO2 nanocomposites by sol–gel method ☆: Influence of modifiers

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Magnetism and transport properties of layered rare-earth cobaltates Ln0.3CoO2

O

PbTiO3 SrTiO3, and PbTiO3-Al2O3 composite and multilayer films prepared by sol-gel technique

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Chemical Solution Deposition and Infrared Study of K(Ta,Nb)O3 Thin Films

perovskite series (