Methods and apparatus for magnetic particle analysis using diamond magnetic imaging
Inventors
Connolly, Colin B. • Randall, Jeffrey D. • Adamson, Seabron C.
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10845449-B2
Publication Date
2020-11-24
Expiration Date
Abstract
The present application discloses methods and apparatus for measuring the arbitrary magnetic response of many individual magnetic particles at once, using a plurality of magnetic images of the magnetic particles acquired over a range of magnetic conditions.
Core Innovation
The invention provides a wide-field diamond magnetic imaging method for determining properties of magnetic particles. It generates a set of magnetic images of a plurality of magnetic particles positioned on a sensing surface of a diamond sensor under different magnetic conditions created by reversing the direction of an externally-applied magnetic field applied to the magnetic particles.
The method analyzes the set of magnetic images to measure single-particle magnetization along single-axis magnetization curves and infer magnetic properties. The inferred magnetic properties include magnetic remanence of individual magnetic particles in the plurality of magnetic particles, and can also include magnetic susceptibility, saturation magnetization, magnetic coercivity, thermal variation, or Curie temperature.
The invention also provides a corresponding system that includes a wide-field diamond magnetic imaging apparatus and a computer system coupled for analysis. The apparatus includes a diamond imaging sensor with a sensing surface containing a layer of diamond nitrogen-vacancy (NV) centers, a source of excitation light for inducing NV center fluorescence, and a magnet for applying a bias magnetic field that is moved to reverse the direction of a magnetizing field; a microwave source applies a microwave field to the sensing surface, and an optical imaging system images the NV fluorescence onto an imaging sensor.
Claims Coverage
The document contains three independent claims (clm-00001, clm-00011, and clm-00025). Together, they cover three inventive features focused on wide-field diamond magnetic imaging, computer-based analysis, and determination of single-particle magnetic properties.
Wide-field diamond magnetic imaging with reversed magnetic conditions
Generate a set of magnetic images of a plurality of magnetic particles positioned on a sensing surface of a diamond sensor under different magnetic conditions created by reversing the direction of a magnetizing field applied to the magnetic particles.
Single-particle magnetization along single-axis magnetization curves to infer remanence
Analyze the set of magnetic images to measure single-particle magnetization along single-axis magnetization curves to infer magnetic properties including magnetic remanence of individual magnetic particles in the plurality of magnetic particles.
Determining susceptibility, saturation magnetization, remanence, and/or coercivity from image sets
Analyze the set of magnetic images to determine magnetic susceptibility, saturation magnetization, remanent magnetization, and/or magnetic coercivity of individual magnetic particles in the plurality of magnetic particles.
Across the independent claims, inventive coverage focuses on wide-field diamond magnetic imaging that produces a set of magnetic images under magnetic conditions created by reversing the direction of a magnetizing field, followed by analysis to infer single-particle magnetic properties. The claims specifically support inference of magnetic remanence and also support determination of magnetic susceptibility, saturation magnetization, remanent magnetization, and/or magnetic coercivity.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?