Abstract: A driving system using an intercalation substance as a novel mechanochemical system includes an actuator using the intercalation substance and driven by exchange of solutions or by changing concentration of a solution, and a solution supplier that supplies the actuator with the driving solution or solutions. The actuator is composed of one or more cylindrical or fiber-shaped elements each extending in the expanding and contracting direction of the intercalation substance, or one or more film-shaped or plate-shaped elements each having a major surface extending vertically of the expanding and contracting direction of the intercalation substance. The driving system is used as artificial muscle, for example.

Abstract: A method of producing a bismuth layered compound that includes the steps of providing a substrate, dissolving Bi, Sr and Ta containing compounds in an organic solvent to form a solution having a Bi:Sr:Ta volume ratio of 2:1:2, evaporating the solution and depositing the evaporated solution onto the substrate, heating the substrate to form a thin film having a fluorite structure, and heating the thin film in an oxidizing atmosphere to convert the thin film having a fluorite structure to a thin film comprising Bi2SrTa2O9.

Abstract: A layer-structured oxide exhibiting a paraelectric characteristic and a layer-structured oxide having a preferable remanent polarization, and a process of producing the same. A layer-structured oxide containing Bi, a first component Me, a second component R, and O is produced by heating raw materials at a high temperature of about 1400° C. for several ten minutes by a self-flux method using Bi2O3 as a flux. The first component Me is composed of at least one kind selected from a group consisting of Sr, Pb, Ba, and Ca, and the second component R is composed of at least one kind selected from a group consisting of Nb and Ta. The composition formula of the oxide is expressed by Bi2−aMe1+bR2O9+c where a, b, and c are values in ranges of 0<a<2, 0<b≦0.4, and −0.3≦c≦1.4. The layer-structured oxide exhibits a paraelectric characteristic or a ferroelectric characteristic at a composition in a specific range out of the stoichiometric composition.

Abstract: A layer crystal structure oxide, and memory element comprising same, comprising bismuth (Bi), a first element, a second element and oxygen (O), wherein the first element is at least one selected from the group consisting of sodium (Na), potassium (K), calcium (Ca), barium (Ba), strontium (Sr), lead (Pb), and bismuth (Bi), the second element is at least one selected from the group consisting of iron (Fe), titanium (Ti), niobium (Nb), tantalum (Ta), and tungsten (W), and the composition ratio of the bismuth with respect to the second element is larger than the stoichiometric composition ratio, wherein, the composition ratio of the bismuth with respect to the first element is in the range of (2±0.17)/(m−1) including the stoichiometric composition ratio 2/(m−1), where m is an integer from, and including, 2 to 5.

Abstract: It is intended to provide a ferroelectric that exhibits superior ferroelectricity. A ferroelectric provided is an oxide having a layered crystal structure that is composed of Bi, a first element Me, a second element R, and O. The first element Me is at least one element selected from the group consisting of Na, K, Ca, Ba, Sr, Pb, and Bi. The second element R is at least one element selected from the group consisting of Fe, Ti, Nb, Ta, and W. Ninety-eight percent or more of the entire body of the ferroelectric exhibits ferroelectricity. After an oxide having a layered crystal structure has been grown by a vapor-phase method (crystal growth step), electrodes are attached to the oxide having a layered crystal structure and a voltage is applied thereto (voltage application step).

Abstract: Provided are a layered crystal structure oxide showing ferroelectricity or paraelectricity and a process for easily producing the same. A raw material containing Bi.sub.2 O.sub.3 as a flux is heated up to 1330.degree. C. or higher and 1450.degree. C. or lower at a suitable temperature-elevating rate (heating step); the raw material is maintained at this heating temperature for prescribed time (constant temperature step); and then, it is slowly cooled down to 800.degree. C. or higher and 1300.degree. C. or lower at a rate of 1.degree. C./hour or more and 20.degree. C./hour or less (slow cooling step). This makes it possible to evaporate the flux and take out directly Bi.sub.2 SrTa.sub.2 O.sub.9. In this Bi.sub.2 SrTa.sub.2 O.sub.9, Bi is partially substituted with Sr, and oxygen is selectively deficient or disordered. Or, Bi and O in the fluorite layer are relatively displaced each other in the polarization direction.

Abstract: A ferroelectric thin film is subjected to heat treatment in an active oxygen atmosphere containing an oxidizing gas such as ozone, N.sub.2 O, or NO.sub.2, thereby preventing occurrence of oxygen defects (oxygen vacancies) in the thin film, and avoiding a deterioration in dielectric characteristics, ferroelectric characteristics, and electric characteristics required for the ferroelectric thin film, such as a reduction in permittivity, an increase in leakage current, a reduction in remanent polarization, and an increase in coercive electric field. Thus, the ferroelectric thin film having stable characteristics can be formed. Further, a nonvolatile memory cell using this ferroelectric thin film as a capacitor is formed.

Abstract: A production method of a crystal structure oxide that includes the steps of evaporating the material by heating the material to generate a gas phase and precipitating crystals from the gas phase at a precipitating part so as to produce a layer crystal structure oxide. The precipitating part is provided away from the material in a range of greater than or equal to about 10 mm to about 30 mm.

Abstract: Described are a stable semiconductor memory device which is not susceptible to the influence of a heat treatment temperature of a semiconductor substrate of reaction pressure in the CVD method and is free from the reduction in remanence caused by data writing in repetition; and a fabrication process of such a device which comprises forming, by the CVD method, a ferroelectric film containing as a component element bismuth, suing a bismuth alkoxide compound as a raw material, and using the ferroelectric film as a film for the formation of storage capacitance for a semiconductor memory device.

Abstract: The formation of an electrically conductive phase in an dielectric or ferroelectric composed of a bismuth compound is inhibited. Described is a process for producing a bismuth compound, which comprises introducing a gas of starting materials in an atmosphere under a pressure of 0.01 to 50 torr, depositing a precursor of a bismuth compound on a substrate, and thermally treating it in an oxidizing atmosphere.

Abstract: A process is disclosed for making a bismuth layered compound, such as Bi.sub.2 SrTa.sub.2 O.sub.9, by forming mixture of Bi.sub.2 O.sub.3, Ta.sub.2 O.sub.5 and a compound selected from strontium hydroxide or strontium nitrate, grinding the mixture, shaping the ground mixture at elevated temperature and pressure to form a pellet of bismuth strontium tantalum oxide having a fluorite structure and then heating the pellet in a flow of oxygen at 800-1000.degree. C. until a single phase bismuth layered compound is obtained.

Abstract: Provided is a process for preparing a bismuth compound at a heat treatment temperature lower than conventional. A bismuth compound is prepared by the steps of heating under vacuum to form a reduced phase and heating under oxidizing environment of normal or lower pressure.