47results about How to "Maximum polarization" patented technology

The present invention relates to a new method and apparatus for converting heat to electric energy. The invention exploits the rapid changes in spontaneous polarization that occur in ferroelectric materials during phase change. The invention permits robust and economical generation of electric energy from thermal energy, and it can be used in many different applications. In one aspect, the present invention relates to an apparatus for converting heat to electric energy comprising a pair of electrodes; a ferroelectric layer formed there between with a ferroelectric material characterized with a Curie temperature, T_c, such that when the temperature of the ferroelectric material is lower than T_c, the ferroelectric material is in a ferroelectric phase in which very powerful polarization is established spontaneously in the unit cells of the ferroelectric material, and when the temperature of the ferroelectric material is greater than T_c, spontaneous polarization is not established in the unit cells of the ferroelectric material; and a means for alternately delivering a flow of cold fluid and a flow of hot fluid to the ferroelectric layer so as to alternately cool the ferroelectric layer at a first temperature T_L that is lower than T_c, and heat the ferroelectric layer at a second temperature T_H that is higher than T_c, thereby the ferroelectric material of the ferroelectric layer undergoes alternating phase transitions between the ferroelectric phase and the paraelectric phase with temperature cycling.

A method for forming sunglass lenses with a predetermined optical gradient, namely a polarized gradient, transmissivity gradient or color gradient in which an ink jet printer is used to print a gradient pattern on an oriented sheet, with the ink jet printer being provided with a dye, in one embodiment a dichroic dye and in another embodiment an iodine dye. The printed oriented sheet is incorporated into a lens to provide the lens with the associated gradient.

In a method of manufacturing a ferroelectric capacitor, a lower electrode layer is formed on a substrate. The lower electrode layer includes at least one lower electrode film. A ferroelectric layer is formed on the lower electrode layer, and then an upper electrode layer is formed on the ferroelectric layer. A hard mask structure is formed on the upper electrode layer. The hard mask structure includes a first hard mask and a second hard mask. An upper electrode, a ferroelectric layer pattern and a lower electrode are formed by partially etching the upper electrode layer, the ferroelectric layer and the lower electrode layer using the hard mask structure. The hard mask structure may prevent damage to the ferroelectric layer and may enlarge an effective area of the ferroelectric capacitor so that the ferroelectric capacitor may have enhanced electrical and ferroelectric characteristics.

A magnetic thin film being ferromagnetic and exhibiting large spin polarization at room temperature is provided that comprises a substrate (2) and a CO₂Fe(Si_1-xAl_x) thin film (3) formed on the substrate (2) where 0<x<1 and wherein the CO₂Fe(Si_1-xAl_x) thin film (3) has a L2₁ or a B2 structure. There may be interposed a buffer layer (4) between the substrate (2) and the Co₂Fe(Si_1-xAl_x) thin film (3). A tunneling magnetoresistance effect device and giant magnetoresistance effect device using such a magnetic thin film exhibit large TMR and GMR at room temperature, with low electric current and under low magnetic field. Using such a magnetoresistance effect device, a magnetic device and a magnetic apparatus such as a magnetic sensor, a magnetic head or MRAM are provided.

This invention relates to a BFO/BXT laminated capacitor and its preparing method, in which, the capacitor includes: a substrate made of silicon and orderly combined with an oxidation layer, a lower electrode metal layer, a BFO film and an upper metal layer, in which, a BXT induction film is set between the lower electrode metal layer and the BFO film. The method includes: preparation of sol of RFO and BXT precursors and preparation of the capacitor of its laminated structure and the ferroelectric capacitor prepared with this method includes excellent property of anti-fatigue, high residual polarized intensity, low operational voltage and better dielectric property.

The chemical formula Bi4-xNdxTi3O12 relates to the 20-500nm Nd-doped bismuth titanate ferro-electricity thin film, wherein, x denotes the mole percent of Nd in total mole number of Nd and Bi, while the surplus content of Bi element takes up of 5-20% as the total mole number of Bi, Nd and Ti. The preparation method comprises preparing predecessor sol and preparing the thin film, respectively. This product has super anti-fatigue property, high Pr value, lower Vc value, and compatible with CMOS technology.

The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved emission efficiency. The Group III nitride semiconductor light-emitting device includes a base layer, an n-type superlattice layer, a light-emitting layer, and a p-type cladding layer, each of the layers being made of Group III nitride semiconductor. An electron injection adjusting layer comprising a single Al_xGa_1-xN (0<x<1) layer and having a thickness of 5 Å to 30 Å is formed in the base layer. The n-type superlattice layer is a superlattice layer having a periodic structure of an In_yGa_1-yN (0<y<1) layer, an i-GaN layer, and an n-GaN layer. The electron injection adjusting layer has a thickness of 5 Å to 30 Å and an Al composition ratio of 0.15 to 0.5.

The invention relates to a strontium titanate-based lead-free high-energy storage density and high-energy storage efficiency ceramic material and a preparation method thereof. The preparation method comprises the following steps: firstly batching according to a chemical formula (1-x)SrTiO3-x(0.65BaTiO3-0.35Bi0.5Na0.5TiO3), wherein x represents a molar fraction and is greater than or equal to 0.1 but less than or equal to 0.6; ball-milling and drying to obtain a raw material powder body; adding the obtained raw material powder body into a bonding agent for pelleting, decaying for 24-48 hours, pressing into a sheet, performing glue removal treatment and sintering at a temperature of 1250-1350 DEG C to obtain the strontium titanate-based lead-free high-energy storage density and high-energy storage efficiency ceramic material. The ceramic material provided by the invention is simple and stable in preparation process, suitable for industrial production and excellent in energy storage characteristics, the energy storage density calculated based on a ferroelectric hysteresis loop is 0.961-1.403 J/cm<3>, and the energy storage efficiency is 84.77-91.63 percent.

A method for converting heat to electricity by exploiting changes in spontaneous polarization that occur in electrically polarizable materials is described. The method uses an internally generated field to achieve poling during cycling. The internal poling field is produced by retaining residual free charges on the electrodes at the appropriate point of each cycle. The method obviates the need for applying a DC voltage during cycling and permits the use of the electrical energy that occurs during poling rather than an external poling voltage which detracts from the net energy produced per cycle. The method is not limited to a specific thermodynamic cycle and can be used with any thermodynamic cycle for converting heat to electricity by thermally cycling electrically polarizable materials. The electrical energy generated can be used in various applications or stored for later use. An apparatus for converting heat to electricity is also described.

A magnetic tunnel transistor (MTT) is formed having an emitter that is configured to provide unpolarized electrons. A composite base is configured to provide polarization of the unpolarized electrons injected into the base by the emitter based upon a magnetic orientation of the free layer and the self-pinned layer of the base.

In a semiconductor laser device a dual wavelength semiconductor laser chip is joined onto a submount, junction down, to reduce built-in stress produced between the laser chip and the submount and to decrease polarization angles of the two respective lasers. SnAg solder is used to join the dual wavelength semiconductor laser chip onto the submount. When joining, with respect to each of the two lasers, a ratio of a distance between the center line of a waveguide and an end, placed at a lateral side of the laser chip, of a portion joining the laser chip and the submount, to a distance between the center line of the waveguide and another end, placed toward the center of the laser chip, of the portion joining the laser chip and the submount, falls within a range of 0.69 to 1.46.

The present invention is a piezoelectric composition and a piezoelectric element using the piezoelectric composition, the composition being characterized by: having a Perovskite structure represented by general formula ABO3; being represented by composition formula x(Bi0.5K0.5)TiO3-yBi(Mg0.5Ti0.5)O3-zBiFeO3, x+y+z=1 in the composition formula above; and in a triangular coordinate using x, y and z in the composition formula above, having a composition represented by a region which is surrounded by a pentagon ABCDE with apexes of point A (1, 0, 0), point B (0.7, 0.3, 0), point C (0.1, 0.3, 0.6), point D (0.1, 0.1, 0.8) and point E (0.2, 0, 0.8) and which does not include the line segment AE that connects point A (1, 0, 0) and point E (0.2, 0, 0.8).

The invention relates to preparation of an AFE capacitor with high energy storage density and high energy storage efficiency, an anti-ferroelectric film layer and preparation thereof, and a flexible AFE capacitor. The preparation method of the AFE capacitor comprises the following steps: depositing a buffer layer on a substrate; depositing a first electrode layer on the buffer layer; depositing anantiferroelectric thin film layer comprising more than two layers of thin films on the electrode layer; and depositing a second electrode layer on the antiferroelectric film layer to obtain an AFE capacitor, wherein the antiferroelectric thin film layer is deposited through pulse laser, and elements contained in adjacent thin films can be the same or different. According to the AFE capacitor prepared by the invention, the maximum breakdown voltage is improved; meanwhile, according to the AFE capacitor layer prepared by using a method of different excitation number components, the energy storage density and the energy storage efficiency of the AFE capacitor are improved; and the AFE capacitor has excellent fatigue resistance and flexible mechanical properties, the polarization and other properties of the AFE capacitor can be kept in a bent state, and a new way is developed for development and application of novel energy storage equipment.

A liquid crystal layer is formed by filling a space between alignment films provided on both glass substrates with a ferroelectric liquid crystal material having a spontaneous polarization. This ferroelectric liquid crystal exhibits a monostable state in which the average molecular axis of the liquid crystal molecular director is present in substantially one direction in the absence of an applied voltage. When a voltage of a first polarity is applied, the average molecular axis tilts from the monostable position to one side at an angle corresponding to the magnitude of the applied voltage, while, when a voltage of a second polarity having the opposite characteristic to the first polarity is applied, the average molecular axis tilts from the monostable position to a side opposite to the application of the voltage of the first polarity. A maximum tilt angle in the application of the voltage of the first polarity is not less than 35°, more preferably not less than 450°. With the use of a liquid crystal material having a large spontaneous polarization, a high-speed response is realized even when the applied voltage to the liquid crystal material is low.

Achieving resistance reduction of a nitride semiconductor multilayer film reflector. In the nitride semiconductor multilayer film reflector, a first semiconductor layer (104) has a higher Al composition than a second semiconductor layer (106). A first composition-graded layer (105) is interposed between the first and second semiconductor layers (104, 106) so as to be located at a group III element face side of the first semiconductor layer (104), the first composition-graded layer (105) being adjusted so that its Al composition becomes lower as coming close to the second semiconductor layer (106). A second composition-graded layer (103) is interposed between the first and second semiconductor layers (104, 106) so as to be located at a nitride face side of the first semiconductor layer (104). The second composition-graded layer (103) is adjusted so that its Al composition becomes lower as coming close to the second semiconductor layer (106). Energy levels of electrons at bottoms of conduction bands of the first and second semiconductor layers (104, 106) and the first and second composition-graded layers (105, 103) are continuous without band offset. The first composition-graded layer (105) has an n-type impurity concentration of not less than 5×10¹⁹ cm⁻³.

A capacitor includes a pair of electrodes and a ferroelectric film sandwiched between the electrodes. The electrodes are provided perpendicular to the direction of the polarization axis of the ferroelectric film.

The invention discloses a potassium-sodium niobate ceramic with high piezoelectric property and high remnant polarization strength and a preparation method of the potassium-sodium niobate ceramic. Thegeneral chemical formula of the lead-free piezoelectric ceramic is (Na0.5K0.5)NbO3. The potassium-sodium niobate leadless piezoelectric ceramic prepared by a solid-phase method has a high piezoelectric constant d33, a high planar electromechanical coupling coefficient Kp and high microcosmic density, the piezoelectric constant of the ceramic can reach 124 pC/N, and the relative density of the ceramic can reach 95.5% by using a ball-milling bead mixed ball-milling mode of zirconium oxide balls of 5 mm and 2 mm (the mass ratio is 1: 2). Meanwhile, the remnant polarization intensity of the ceramic is 23 mu C/cm<2> and is higher than that of ceramic (10-15 mu C/cm<2>) prepared by a traditional solid-phase method reported in literature. The method has important guiding significance for preparing the high-performance lead-free potassium-sodium niobate-based piezoelectric ceramic by utilizing a traditional solid-phase method.

In a liquid crystal display device that uses a liquid crystal material having spontaneous polarization and is actively driven by a TFT, a voltage corresponding to image data is applied twice by driving the TFT of each pixel electrode on a line by line basis of a liquid crystal panel, during writing in one frame. During erasure in one frame, voltage application to liquid crystal by batch selection of all the pixel electrodes is performed three times. With this three times of voltage application, it is possible to achieve a black display state in each pixel and make the stored charge amount at the liquid crystal in each pixel substantially zero.

An alkaline dry battery includes a positive electrode, a negative electrode, a separator, and an alkaline electrolyte. The separator is provided between the positive electrode and the negative electrode, and the positive electrode, the negative electrode, and the separator are impregnated with the alkaline electrolyte. A battery depolarizer, which is an organic compound having a function of depolarizing both the positive electrode and the negative electrode or an alkaline metal salt thereof, is added to at least the alkaline electrolyte.

The invention belongs to the technical field of chemical materials, and relates to a PAMMA-coated BT/PP nanocomposite dielectric film with controllable shell thickness and a preparation method thereof. The preparation method comprises the following steps: 1) initiatingin-situ free radical polymerization of methyl methacrylate MMA on the surface of barium titanate BT to prepare PMMA-coated BT nanoparticles; 2) carrying out melt blending on the PMMA-coated BT nanoparticles and polypropylene PP for 15 minutes to obtain a sample; and 3) cutting the sample into small samples, and carrying out hot press molding at 190 DEG C and 125 MPa by using a hot press to obtain the PMMA-coated BT/PP nanocomposite dielectric film. The nanomaterial prepared by the invention has the characteristics of uniform core-shell structure, adjustable shell thickness and good dispersion; the dielectric film has good light transmission, excellent flexibility, small dielectric loss, high polarization strength, and synergistically improved breakdown strength and dielectric property; and the preparation method is simple in process and easy to control.