Mohammad Moradi, Forouzan Habibi, Asieh Rafiee,
Volume 17, Issue 2 (6-2023)
Abstract
In this study, copper cobalt ferrite nanoparticles were synthesized by chemical formula Co1-xCuxFe2O4 and (x=0, 0.2, 0.4, 0.6, 0.8, 1) by co-precipitation method. The X-ray diffraction pattern of the samples confirmed the single-phase spinel structure of the fabricated nanoparticles and the average size of the crystals was calculated from the entire width of the diffraction peak with the highest intensity and Scherrer relationship. Using transmission electron microscope images, the nanoparticle size was about 10 nm. The magnetic properties of copper cobalt ferrite nanoparticles were measured by AGFM and it was seen that with increasing substitution of copper Cations instead of cobalt Cations in the samples, the amount of induction decreased and the saturation magnetization first increased and then decreased. In order to investigate the Faraday effect on copper cobalt ferrite nanoparticles, the transmittance values were measured using a laboratory experiment and their graphs were plotted in terms of the applied magnetic field, all of which were in agreement with the theory. In addition, transmittance was investigated for two angular positions of the analyzer at -45˚ and +45˚ in different fields.
Maliheh Ranjbaran, Reza Sedeyan, Amin Zamani, Mohammad Mehdi Tehranchi, Seyed Mohammad Hosein Khalkhali, Seyedeh Mehri Hamidi,
Volume 17, Issue 2 (6-2023)
Abstract
The measurement of magnetic field generated by heart activity is crucial for the diagnosis and treatment of heart diseases and failures. Atomic magnetometers are an excellent choice for detecting bio-magnetic fields due to their comparable sensitivity to superconducting quantum interference devices, lower manufacturing costs, and lack of requirement for low temperatures. These magnetometers detect the magnetic field resulting from heart activity by measuring the Zeeman energy splitting and changes in laser light intensity as it passes through an alkali metal vapor cell. To improve the sensitivity of the measurements, this study presents a gradiometer design that utilizes two atomic magnetometers to eliminate environmental magnetic noise. By using a derivative technique, the homogeneous noises in both magnetometer channels are effectively eliminated. The gradiometer is capable of detecting the magnetic field produced by a frog's heart with a sensitivity of 860 fT/√Hz even without magnetic shielding and in the presence of the Earth's field. This gradiometer design can be expanded to include multiple channels for mapping the heart's magnetic field.
