**3.4 Superconducting quantum interference device magnetometry**

Superconducting quantum interference device magnetometry (SQUID) is a tool for calculating the magnetic fields of nanoscale objects. Nanomaterials, in some cases, exhibit properties that are different from those in the plural form due to their small size and awareness of local conditions. As the material decreases in size, it progresses from multiple domains to a single domain and eventually to a superparamagnetic state. Standard SQUID measurements produce features such as magnetization filtration (MS), magnetization remanence (Mr.), and inhibitory temperature (Tb). On the side of NPs, the magnetic response of particular molecules can be tested by SQUID. A magnetic scanner that incorporates nanoSQUID features that have already been created recently made about a sharp quartz apex. NanoSQUID is considered the most inspiring investigation into nanoscale magnetic imaging and spectroscopy. The nanoSQUID sensor requires a Josephson subcutaneous micron coating, provided by two Dayem nano bridges (nano-constriction of the superconducting film), made of electron beam lithography {focused ion beam (FIB) with the same length and width and compliance length. The main SQUID requirement developed to obtain a magnetic NPS is a small SQUID area. Loop sizes should prefer the NPS integrated [58] to achieve the most fantastic merging feature. About magnetic resonance | microscopy or magneto-optic spin recognition, nanoSQUID provides the advantage of the exact magnitude of the magnetic field in small spin paths. In addition to its inefficient construction with the step of nanopatterning alone, Dayem nanoSQUID bridges can withstand the magnetic field used inside the SQUID loop plane [59]. The test set of the nanoSQUID is shown in **Figure 2**.
