178 results about "Residual polarization" patented technology

A system and method for measuring resistance of a polarizing material are disclosed. The system includes a voltage divider circuit having a first resistive element of known resistance and the polarizing material of unknown resistance and a processing unit. The processing unit is electrically-coupled to the voltage divider circuit and adapted to apply a voltage across the voltage divider circuit. A first input / output (I / O) pin is electrically-coupled between the processing unit and the first resistive element. A second pin is electrically-coupled between the processing unit and a junction between the polarizing material and the first resistive element. A controller is adapted to cause the second pin to short the polarizing material after a measurement is completed, to bleed off any residual polarization from the capacitive element of the polarizing material.

The polarity inversion cycle of a voltage applied to a liquid crystal layer is set to at least 2-frame cycle, or more preferably to as long as about 10 sec. Accordingly, a flicker that could not have been prevented at a polarity inversion cycle of about one frame can be prevented, and a longer inversion cycle can reduce power consumption. A material low in ion reactivity and small in residual polarization is used as a liquid crystal material or an orientation film material, thereby preventing the occurrence of a residual DC component in a liquid crystal layer and the deterioration of display quality despite a longer polarity inversion cycle. In the case of an LCD provided with a minimal transmittance with respect to an applied voltage, black can be accurately displayed by, for example, regulating a common electrode potential so that an applied voltage at which the transmittance of a liquid crystal shows a minimum value during an anodic application period is equal to that during a cathodic application period.

The invention belongs to the field of micro-nano semiconductor optoelectronic devices, and particularly relates to a phototransistor based on a ferroelectric gate dielectric and a thin layer MoS2 channel and a preparation method thereof. The phototransistor comprises a source electrode, a leakage electrode, a channel, a gate electrode, a gate dielectric, a metal pad, and a substrate. The source electrode and the leakage electrode are graphene, the channel is thin layer MoS2, and the gate dielectric is a PZT ferroelectric membrane. Compared with existing similar phototransistor, the phototransistor has the following advantages that first, a high dielectric coefficienet of the PZT ferroelectric membrane helps improve the adjustment performance of the gate electrode for a channel carrier; second, the PZT ferroelectric membrane can adjust the channel carrier with surplus polarity field strength, so that the power consumption of the device is lowered; third, compared with organic ferroelectric material P (VDF-TrFE), the PZT ferroelectric membrane has the advantages of high surplus polarity, low coercive field strength, stable property and compatibility with microelectronic process; and fourth, as the source electrode and leakage electrode, the graphene can improve the signal light transmittance, and improve the light response degree and gain of the device.

A polyamide obtained by polycondensation of a diamine component containing at least 50 mol % of 2-methyl-1, 5-pentanediamine and a dicarboxylic acid component containing at least 50 mol % of azelaic acid, comprising the following properties of (1) to (4), (1) when a stretched film is polarized in an electric field of 200 MV / m, a remanent polarization is at least 30 mC / m<2>, (2) the relative viscosity of a 1 g / dl solution of the polyamide in 96% concentrated sulfuric acid at 25 ° C. is 1.3 to 5.0, (3) the glass transition temperature is 80° C. or less and a calorific value at a cooling crystallization exotherm peak is 5 J / g or less, and (4) it is soluble in an amount of at least 5 mass % at 25 ° C. in at least one selected from methanol, ethanol and 2-propanol, and a resin composition containing the above polyamide and an electrically conductive material.

The invention discloses a method for preparing a bismuth ferric film material. The method adopts a pulsed laser deposition technology; a bismuth ferric film is deposited on a silicon substrate coveredby an electrode; and the bismuth ferric film with high remnant polarization is obtained by adjusting process parameter in deposition process and in-situ annealing. The method has the advantages thatthe single-crystal silicon is taken as the substrate material, the remnant polarization of the obtained bismuth ferric film is higher than that of the traditional ferroelectric film, and the bismuth ferric film is an ideal material for silicon-based ferroelectric components such as a ferroelectric memory and the like.

The invention provides a multiferroic Bi1-xRExFe0.97-yMn0.03TMyO3 / CoFe2O4 composite film and a preparation method thereof. The composite film comprises a Bi1-xRExFe0.97-yMn0.03TMyO3 crystalline state film and a CoFe2O4 crystalline state film. The preparation method comprises the following steps of respectively preparing Bi1-xRExFe0.97-yMn0.03TMyO3 precursor solution and CoFe2O4 precursor solution; spin coating on a substrate to prepare a plurality of layers of CoFe2O4 films, spin coating on the CoFe2O4 films to prepare a plurality of layers of Bi1-xRExFe0.97-yMn0.03TMyO3 films and accordingly obtaining a target product. According to the multiferroic Bi1-xRExFe0.97-yMn0.03TMyO3 / CoFe2O4 composite film and the preparation method thereof, the device requirement is simple, the prepared film is good in homogeneity, the doping content is easy to control, the ferroelectric property and the ferromagnetic property of the film are improved to a large extent, and the film is high in residual polarization value and residual polarization value.

The invention relates to samarium-oxide-doped modified lead zirconate titanate ferroelectric ceramic and a preparation method thereof. The ferroelectric ceramic has a composition general formula as follows: Pb1-xSmx(ZryTi1-y)0.98Nb0.02O3, wherein x is more than 0 and not more than 0.1, and y is not smaller than 0.9 and not more than 0.97. The residual polarization strength Pr of the ferroelectric ceramic ranges from 4 mu C / cm<2> to 36 mu C / cm<2>, so that the energy storage density of the ferroelectric ceramic is regulated in a wider range, and the performance requirement of the output power design of a pulse power supply is met. According to the process, formula design, weighing, mixing, powder synthesizing and sintering are carried out according to design requirements; and the addition amount of Sm2O3 is low, and no extra process program is needed. Compared with the traditional process in which a pore-forming agent is added, the preparation method has the advantage that the use of the pore-forming agent and processes such as uniform dispersion are reduced. Accordingly, the invention is simple in process and suitable for scale production.

An apparatus for separating fluorescent light from light elastically scattered / reflected from a material illuminated with a broadband illumination source includes a polarization discriminator, which separates the substantially polarized elastically scattered / reflected light from the unpolarized fluorescent light, and a spectrometer to analyze the full and separated reflectance spectra. A linear polarizer may be provided to polarize the illumination source. A method for separating fluorescence light induced in a material by broadband light from an elastic scattering / reflection component includes providing polarization discrimination to separate the components, the fluorescence light being substantially unpolarized, and spectrally analyzing the reflectance components. The method may include linearly polarizing the light source. A fluorescence spectra may be extracted from a minimum reflectance spectra or from a residual polarization reflectance spectra.

An embodiment of the invention discloses a method and a device for decomposing objective scattering ingredients of a polarized SAR (synthetic aperture radar). The method comprises the following steps of selecting a volume scattering model based on polarized SAR image data to be processed; extracting the maximum volume scattering power of the polarized SAR image data to be processed according to the polarized SAR image data to be processed and the volume scattering model; acquiring residual polarization coherence matrix of the polarized SAR image data to be processed according to the polarized SAR image data to be processed, the volume scattering model and the maximum volume scattering power value, and performing characteristic decomposition on the residual polarization coherence matrix to obtain the characteristic value and the characteristic vector of the residual polarization coherence matrix; calculating an objective scattering mechanism decision value according to elements of the characteristic vector; and determining even-order scattering and / or surface scattering ingredients of the polarized SAR image data to be processed according to the objective scattering mechanism decision value, and determining power values corresponding to the even-order scattering and / or surface scattering ingredients.

The invention discloses a preparation method of an organic ferroelectric film with high polarization intensity. PbTiO3 nanosheets and PVDF-TrFE (polyvinylidene fluoride-trifluoroethylene) are taken as main raw materials, firstly, PVDF-TrFE is dissolved in tetrahydrofuran, a proper quantity of PbTiO3 nanosheets are added, and a turbid liquid is obtained; the PbTiO3 nanosheets are uniformly dispersed in a solution through ultrasonic treatment, a clean substrate is spin-coated with the solution uniformly with a spin-coating method, and a film is formed and subjected to heat treatment at the temperature of 180 DEG C. The preparation technology is simple, the process is easy to control, the prepared organic ferroelectric film has an oriented micro-nano structure and also has excellent electrical properties, and the residual polarization is up to 12.4 mu C / cm<2>.

The invention relates to an average length detection device and method as well as a light coherent receiver. The average length detection method is used for detecting whether the average length of an averager used by a polarization crosstalk eliminating device in the receiver is long or short. The method comprises the steps of determining the value of a residual polarization crosstalk coefficient of the receiver, and determining the index of whether the average length of the averager is long or short according to the value of the determined residual polarization crosstalk coefficient.

The invention provides a LaSrMnCo codoped bismuth ferrite multiferroic film and a preparation method thereof. A Bi(0.97-x)LaxSr0.03Fe0.94Mn0.04Co0.02O3 multiferroic film, namely the LaSrMnCo codoped bismuth ferrite multiferroic film, is prepared by taking bismuth nitrate, lanthanum nitrate, strontium nitrate, ferric nitrate, manganese acetate and cobalt nitrate as raw materials (bismuth nitrate of excessive 5 percent), taking ethylene glycol monomethyl ether and acetic anhydride as solvents and using a spin-coating method and a layer-by-layer annealing process. A sol-gel process is adopted, spin-coating and layer-by-layer annealing methods are adopted, equipment requirements are simple, experimental conditions are easy to realize, the film is suitably prepared on a large surface and an irregularly shaped surface, chemical components are accurately controllable, the multiferroic property of the BiFeO3 film can be improved, the prepared the LaSrMnCo codoped bismuth ferrite multiferroic film has high uniformity and is a multiferroic film with high residual polarization value and low coercive field, and the ferroelectric and dielectric properties of the film are effectively enhanced.

The invention discloses a BiFe1-yMnyO3 epitaxial composite film. The BiFe1-yMnyO3 epitaxial composite film comprises a (100)-orientation LaNiO3 electrode layer, a (001)-orientation Bi4-xLnxTi3O12 transition layer and a (100)-orientation BiFe1-yMnyO3 main body layer in sequence from bottom to top, wherein Ln is lanthanide, x is molar equivalent of the lanthanide and greater than 0 and less than I, y is molar equivalent of Mn and greater than 0 and less than or equal to 0.05. The invention also discloses a preparation method of the BiFe1-yMnyO3 epitaxial composite film. The preparation method combines a chemical solution method with a rapid annealing process by layers, and adopts an epitaxial growth method for preparing the composite film. The prepared composite film consists of three layers, wherein a good epitaxial relationship exists between layers which are both in an epitaxial growth form. The composite film has the advantages of aging prevention, leakage reactance, and high residual polarization (-80 mu C / cm<2>), thus having a good practical prospect in the future ferroelectric and piezoelectric film devices.