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EN
The electrical properties and behaviour in constant magnetic field of fourfold expanded GaSe matrix intercalated with SmCl 3 guest were investigated by means of impedance spectroscopy and cyclic voltammetry. It was determined that the synthesized GaSe< SmCl 3> clathrate of 4-fold expansion demonstrates the coexistence of mechanisms of generation, transformation and accumulation of electric energy on a quantum level. These mechanisms are driven from external sources of magnetic, thermal and electric field without Faradaic reactions. Therefore, investigated GaSe< SmCl 3> structure is of great attraction in multivoltaics as a prototype of new class of materials. Quantum mechanical model of electro motive force of spin nature is proposed. The main focus of work lies in the prospects of synthesized clathrates for the development of power nanosources and gyrator-free delay nanolines controlled by means of magnetic field.
2
Content available remote Structural and magnetic properties of gadolinium modified BiFeO3
EN
This paper reports the synthesis and characterization of the Bi0.94Gd0.06FeO3 sample obtained by solid state reaction method. The structural and morphological analysis was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rietveld refinement analysis, confirming the obtaining of a rhombohedral crystalline phase and R3c space group (a = b = 5.577 Å and c = 13.847 Å), with an interconnected structure. Studies by X-ray photoelectron spectroscopy (XPS) revealed trivalent oxidation states of Bi, Fe and Gd ions. The synthesized sample exhibited a non-linear M–H loop indicating a weak ferromagnetic behavior with a remnant magnetization of 6.34 emu∙mol−1 and a coercive field of 295 Oe. The obtained structural and magnetic characteristics make these materials of great interest as multiferroic components.
EN
In this paper we present the results of investigations into ceramic samples of solid solution (1-x)(PbZr0.53Ti0.47O3)-x(PbFe0.5Ta0.5O3) (i.e. (1-x) PZT-xPFT) with x = 0.25, 0.35 and 0.45. We try to find the relation between the character of dielectric dispersion at various temperatures and the composition of this solution. We also describe the magnetic properties of investigated samples. With increasing the content of PFT also mass magnetization and mass susceptibility increase (i.e. magnetic properties are more pronounced) at every temperature. The temperature dependences of mass magnetization and reciprocal of mass susceptibility have similar runs for all the compositions. However, our magnetic investigations exhibit weak antiferromagnetic ordering instead of the ferromagnetic one at room temperature. We can also say that up to room temperature any magnetic phase transition has not occurred. It may be a result of the conditions of the technological process during producing our PZT-PFT ceramics.
4
Content available remote Magnetyczno-dielektryczne właściwości polikrystalicznej ceramiki GdxBi1-xFeO3
PL
Roztwory stałe GdxBi1-xFeO3 (x = 0,0; 0,05; 0,1; 0,15) przygotowano według standardowej technologii ceramicznej. Pomiarów pętli histerezy magnetycznej GdxBi1-xFeO3 dokonano w zakresie temperatur od 5 do 300 K w polu magnetycznym o indukcji do 8 T. Wymiana jonów bizmutu przez jony gadolinu prowadzi do pojawienia się stanu słabego ferromagnetyzmu. Właściwości dielektryczne układu GdxBi1-xFeO3 zbadano w zakresie częstotliwości od 400 do 2500 cm-1.
EN
GdxBi1-xFeO3 (x = 0.0; 0.05; 0.1; 0.15) solid solutions have been prepared by a conventional ceramic processing technique. The magnetic loops of GdxBi1-xFeO3 were measured over the temperature range from 5 K to 300 K in magnetic field up to 8 T. Substitution of the gadolinium ions for the bismuth ions leads to the appearing of a weak ferromagnetic state. Dielectric properties of the GdxBi1-xFeO3 system over a frequency range of 400–2500 cm-1 have been systematically investigated.
EN
Nondoped BiFeO3 (BFO) and doped Bi0.9La0.1Fe0.9Mn0.1O3 (BLFMO) thin films (d = 200-350 nm) were grown at 650- 750 °C by RF sputtering on Si and SrTiO3(100), coated by conductive LaNiO3 films and La2/3Ca1/3MnO3/SrRuO3 bilayers. The complex dielectric permittivity of the films was measured at room temperature in the frequency range from 10 MHz to 10 GHz using parallel plate capacitor structures. Dielectric properties of the polycrystalline BFO films were compared with those of the epitaxial quality BLFMO films, and it was seen that the latter has better microwave performance than the former. The dielectric losses were below 0.05 at 1 GHz frequency, which may be acceptable for microwave applications.
EN
The present work is dedicated to the functional description of eutectic composites containing rare earth ferrite - REFeO3. Materials that fall under this cathegory exhibit the spontaneous dielectric and magnetic polarization - they behave as ferroelectrics and ferromagnets and can be "tuned" by small additions of other rare earth elements without causing large crystal lattice distortions. Special attention was paid to multifunctionality that, in the majority of cases, comes from the control of the structural refinement with the supercooling of the crystallizing liquid.
PL
Niniejsza praca poświęcona jest opisowi funkcjonalności eutektycznych kompozytów na osnowie ferrytów metali ziem rzadkich - REFeO3. Materiały należące do tej grupy wykazują jednocześnie spontaniczną polaryzację dielektryczną (ferroelektryczność) i magnetyczną (ferromagnetyzm) a ponadto dają się "stroić" za pomocą domieszek innych metali ziem rzadkich nie powodując silnych zniekształceń sieci krystalicznej. Szczególną uwagę zwrócono na wielofunkcjonalność wynikającą w dużej mierze z możliwości sterowania rozdrobnieniem struktury za pomocą zmiany przechłodzenia krystalizującej cieczy.
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