Material Sciences Indicator structures for magneto-optic imaging of magnetic irreguliarities
Indicator structures for magneto-optic imaging of magnetic irreguliarities
Description
Imaging method is based on magneto-optic (MO) Faraday effect that allows a transformation of spatially non-uniform distribution of the inspected specimen leakage field into an optical contrast image. Indicator structure consists of soft magnetic epitaxial film of Bi-substituted rare earth iron garnet grown by liquid phase epitaxy (LPE) method with deposited mirror and protective layer. The general view of the samples is shown on the fig. 1. A principle of magneto-optic visualization using the Bi-substituted iron garnet LPE film is shown on fig. 2.
Innovative Aspect and Main Advantages
The developed LPE technological process ensures obtaining the following indicator structures:
- structure diameter – till 3" (76.2 mm);
- structure thickness – 0.5…30 μm;
- specific Faraday rotation 2F
@500 nm – till 5·104 deg/cm;
@633 nm – till 2·104 deg/cm;
@1300 nm – till 2·103 deg/cm.
Areas of Application
Indicator structures are used for non-destructive testing and evaluation of hidden flaw, non-uniformities and microdefects in ferromagnetic, conductive and super conductive materials, recognizing and authentication of magnetic protection marks on banknotes and securities, visualization of magnetic records, topographing of electrical currents in planar conductor structure, etc.
Fig. 1 Substrates and MO indicator structures
Fig. 2 Principle of magneto%optic visualizing 1 – light source,
2 – polarizer, 3 – beam split mirror,
4 – transparent substrate, 5 – indicator layer,
6 – mirror layer, 7 – inspected specimen,
8 – analyser, 9 – CCD camera
Stage of Development
We are seeking for the partners for joint development and further fabrication of MO visualizers on the base of developed indicator structures for different applications. The fabrication technology for Bi-substituted rare earth iron garnet films is well worked out in laboratory version. The SRC "Carat" is provided with needed technological and analytical equipment only on 80 %.
Contact Details
Lviv Regional Department of Academy of the Technological Sciences of Ukraine
Contact person: Dr. N. Vakiv
202, Stryjska st., Lviv, 79031, Ukraine
Тel: 38 0322 63 1065
Fax: 38 0322 94 9735
E-mail:
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