Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y25/00—Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/08—Metals
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F41—WEAPONS
  • F41H—ARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
  • F41H3/00—Camouflage, i.e. means or methods for concealment or disguise
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/20—Conductive material dispersed in non-conductive organic material
  • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/0036—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties showing low dimensional magnetism, i.e. spin rearrangements due to a restriction of dimensions, e.g. showing giant magnetoresistivity
  • H01F1/0045—Zero dimensional, e.g. nanoparticles, soft nanoparticles for medical/biological use
  • H01F1/0063—Zero dimensional, e.g. nanoparticles, soft nanoparticles for medical/biological use in a non-magnetic matrix, e.g. granular solids
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/018—Dielectrics
  • H01G4/20—Dielectrics using combinations of dielectrics from more than one of groups H01G4/02 - H01G4/06
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N15/00—Thermoelectric devices without a junction of dissimilar materials; Thermomagnetic devices, e.g. using the Nernst-Ettingshausen effect
  • H10N15/10—Thermoelectric devices using thermal change of the dielectric constant, e.g. working above and below the Curie point
  • H10N15/15—Thermoelectric active materials

Definitions

• the invention relates to a method for materials according to the preambles of claims 1 and 2 and their use.
• the invention is based on knowledge about the electrical conductivity of mutually insulated, electrically conductive particles, for example indium crystals, with diameters in the order of 1 nm to 1000 nm, which are in a non-conductive or diamagnetic material; this conductivity decreases rapidly with decreasing diameter approximately proportional to its third power, as shown in FIG. 1 for indium at a temperature of approximately 300 K., where x is the diameter and ⁇ is the electrical conductivity. Note the double logarithmic scale and the area of the experimental measurements designated "experiment".
• the object of the invention is to make these phenomena technically usable in the production of materials with certain dielectric and / or magnetic properties that are desired in a wide range.
• claims 1 and 2 specify the measures for preselecting predetermined dielectric, pyroelectric and magnetic properties in the production of materials separately from one another. While the subclaims deal with exemplary uses of these materials, although there are other uses of the same.
• Mesoscopic here means a range of dimensions between macroscopic and microscopic, ie approximately between 1 nm and 1000 nm.
• the result is a heterogeneous medium in the form of an indium colloid with, for example, 0.5% by volume of the metal components.
• This can be increased to a filling factor f of approximately 0.20 to approximately 0.35 by subsequent centrifugation at approximately 70,000 times the acceleration due to gravity. If the colloids are heated, the particles start to aggregate, which leads to particle sizes of several 100 nm depending on the heating temperature and the heating time. Deep-melting materials are particularly suitable for this.
• the particle growth can be arbitrarily interrupted by subsequent cooling and continued by reheating the samples in the sense of FIG. 2.
• Other suitable systems are e.g. B. metal or semiconductor particles in a ceramic or plastic matrix (Trägermat.erial).
• FIG. 3 shows the X-ray intensity J ⁇ k (in arbitrary units) as a function of the deflection vector k for an indium colloid with a fill factor of approximately 0.25, namely on the one hand square measuring points (curve A) in front of the Heating and on the other hand curve B after heating. If a sample with less indium than in (3) is used, curve C (triangular measuring points) results
• FIG. 4 serves to explain the conductivity measurement of mesoscopic metal particles.
• a microwave method is used for this.
• the complex dielectric function and thus the electrical conductivity is obtained from the microwave absorption and the phase shift of a multilayer test specimen (sandwich).
• the oscillation time of the used microwave measurement frequency of 10 GHz is 10 - 10 s and is therefore more than four orders of magnitude greater than a typical relaxation time of a metal at room temperature, whereby the measured microwave conductivity also approximately applies to direct current.
• the effective conductivity of the entire heterostructure is measured taking into account the dielectric data of the pure oil matrix.
• this method can also be used to measure components in other insulating matrices, for example water in oil in the form of a microeraulsion, indium in oil in colloidal form or platinum in ceramic.
• FIG. 4 means ( ) the effective complex dielectric function of the metal particles in oil that is filled in Teflon washers.
• This Teflon has a dielectric function ( ⁇ T ).
• the size of the particles it is possible to specify any value of their conductivity that lies between that of insulators and metal, for example in the production of microwave absorbers.
• the method according to the invention can also be used advantageously for materials that use resistors or other line components (capacitors, Transformers) in VLSI circuits and integrated microwave circuits.
• the material produced according to the invention can optionally be selected according to the desired absorption factor, reflection factor and frequency range. This can be used in the directional antenna technology in many applications with great advantage an antenna cover, for. B. build a radome of a radar antenna, which is transparent for the operating wavelength, but not for enemy radiation incident in the military.
• a radar camouflage is possible with the material produced by the method according to the invention in such a way that quasi total absorption takes place, but this can result in "hole formation" in large surroundings in an environment with radar reflecting properties, which makes the camouflage illusory.
• it is more expedient to achieve certain radar echo structures for example to simulate a reflection image of the surrounding space or to consciously produce radar targets.
• components such as, for. B. capacitors and resistors in a small space.
• the invention can advantageously be used for components for beam guidance and beam filtering, such as, for example, because of the selectable dielectric properties.
• FIG. 5 have uncooled pyroelectric IR detectors according to the prior art at low signal frequencies f a high detectivity D *, which, however, is disadvantageous
• the frequency drop of D * can advantageously be shifted towards higher frequencies (dashed curve).

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Nanotechnology (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Electromagnetism (AREA)
• General Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Dispersion Chemistry (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Photometry And Measurement Of Optical Pulse Characteristics (AREA)
• Aerials With Secondary Devices (AREA)

Applications Claiming Priority (4)

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• 1988
  • 1988-01-26 DE DE3802150A patent/DE3802150A1/de active Granted
  • 1988-07-08 WO PCT/EP1988/000609 patent/WO1989000754A1/de not_active Application Discontinuation
  • 1988-07-08 JP JP63505999A patent/JPH02500869A/ja active Pending
  • 1988-07-08 EP EP88905815A patent/EP0323990A1/de not_active Withdrawn

Non-Patent Citations (1)

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