70 results about "Lead magnesium niobate" patented technology

High-capacity capacitors and gate insulators exhibiting moderately high dielectric constants with surprisingly low leakage using amorphous or low temperature films of perovskite type oxides including a titanate system material such as barium titanate, strontium titanate, barium strontium titanate (BST), lead titanate, lead zirconate titanate, lead lanthanum zirconate titanate, barium lanthanum titanate, a niobate, aluminate or tantalate system material such as lead magnesium niobate, lithium niobate lithium tantalate, potassium niobate and potassium tantalum niobate, a tungsten-bronze system material such as barium strontium niobate, lead barium niobate, barium titanium niobate, and Bi-layered perovskite system material such as strontium bismuth tantalate, bismuth titanate deposited directly on a silicon surface at temperatures about 450° C. or less.

The invention discloses a lead indium niobate-lead magnesium niobate-lead titanate relaxor ferroelectric textured ceramic with high electrical properties and a preparation method and application of the textured ceramic and relates to the field of piezoelectric and ferroelectric materials. The invention aims to solve the problem that an existing PIN-PMN-PT single crystal component is segregated, the available size is limited, the mechanical property is poor, and the PIN-PMN-PT ceramic is low in electric property. The chemical formula is xPb(In<1 / 2>Nb<1 / 2>)O<3>-(1-x-y)Pb(Mg<1 / 3>Nb<2 / 3>)O<3>-yPbTiO<3>-avol.%BaTiO<3>. The method comprises the steps: preparing PIN-PMN-PT fine crystal matrix powder by a two-step synthetic method; preparing a BaTiO<3> sheet micro-crystal template by virtue of a local chemical micro-crystal substitution method; and preparing the PIN-PMN-PT-based ternary relaxor ferroelectric textured ceramic orientated along [001] height by adopting a template grain orientated growth technology. The ceramic is applied to the field of ultrasonic transducers, piezoelectric drivers and piezoelectric sensors.

The invention discloses a preparation method of lead magnesio-niobate-lead titanate ceramic for solving the technical problem that dielectric loss of the lead magnesio-niobate-lead titanate ceramic prepared by the conventional method is large. The technical scheme is that: weighing and dosing analytically pure MgO (magnesium oxide), Nb2O5 (niobium oxide), PbO (lead oxide) and TiO2 (titanium dioxide) according to the chemical metering ratio (1-x)Pb(Mgl / 3Nb2 / 3)O3-xPbTiO3 (x is smaller than or equal to 0.07 and greater than or equal to 0.01); drying and pressing the materials into blocks after ball-milling, crushing the materials to obtain MgNb2O6 (magnesium niobium oxide) powder; adding TiO2 and PbO to MgNb2O6 powder and then ball-milling, and obtaining PMN-PT (lead magnesium niobate) powder by pressing and burning the material into large blocks; sieving and pre-pressing the PMN-PT powder into wafer, and carrying out isostatic pressing pressure molding; and carrying out heat preservation for 1-4 hours on the molded wafer at 1175-1250 DEG C, and then sintering the molded wafer into ceramic. Two systems are composited together, so that the prepared lead magnesio-niobate-lead titanate ceramic has combination properties of two different systems of lead magnesio and niobate-lead titanate, and has high dielectric constant under the condition that the temperature is 300K same as that of a background technology, meanwhile, lower dielectric loss and higher dielectric tenability are respectively kept at 0.007-0.011 and 63-87% at the same time.

The invention discloses a new method for realizing adjustable charge-orbital ordering characteristic in a (001) oriented perovskite manganese oxide thin film and use thereof. In the method, (001) oriented lead magnesium niobate-lead titanate (PMN-PT) with high reverse piezoelectric performance is used as a substrate, the lattice mismatch of the substrate and the perovskite manganese oxide is controlled to be 1 to 3 percent to ensure that the thin film has a large in-plane tensile strain during epitaxial growth, and thus, the charge-orbital ordered transformation is induced. The chemical general formula of the thin film is Re1-xAexMnO3, wherein x ranges from 0 to 1; Re is one or more than two of La, Ce, Pr, Eu, Ho, Nd and Sm; and Ae is one or more than two of Ca, Sr, Ba, Ce, Sn, Y and Hf. Furthermore, the state of the charge-orbital ordered phase in the thin film can be adjusted by applying a bias electric field onto the substrate, and thus, the magnetoresistance of the thin film can be controlled.

A method of making a single crystal of lead magnesium niobate-lead titanate (PMN-PT). The method includes providing a flat-bottomed iridium crucible containing PMN-PT starting material, and placing the crucible into a vertical Bridgman furnace having at least two temperature zones, which is subsequentially pressured with an inert gas. The crucible then descends into the temperature zones of the vertical Bridgman furnace. The temperature zones of the vertical Bridgman furnace include a first temperature zone having a temperature higher than a melting temperature of the PMN-PT material and a second temperature zone having a temperature less than the melting temperature of the PMN-PT material. The single crystals of the PMN-PT prepared using the above-described method exhibits a [110] crystal orientation and may be used in electroacoustic transducers. The electroacoustic transducers are useful in devices that detect or generate acoustic waves.