magneettisuusmittauksiin

magnetisuusmittaus, also known as magnetic measurement, refers to the experimental determination of magnetic properties of materials. The term is widely used in physics, materials science, and electrical engineering to evaluate parameters such as magnetization, magnetic susceptibility, coercivity, remanence, and saturation magnetization. These values are fundamental for characterizing ferromagnetic, ferrimagnetic, antiferromagnetic, and paramagnetic materials and for assessing performance in applications ranging from data storage to biomedical devices.

The most common instruments for magneettisuusmittauksiin are vibrating sample magnetometers (VSM), superconducting quantum interference devices (SQUID), and magneto‑optical Kerr effect setups. VSM detects changes in the magnetic moment of a sample by measuring the induced voltage in pickup coils as the sample vibrates under a magnetic field. SQUIDs provide ultra‑high sensitivity by measuring quantum interference of superconducting loops, allowing detection of magnetic moments below 10‑7 emu. Magneto‑optical Kerr effect techniques use polarized light reflected from a magnetized surface to determine surface magnetization with nanometer depth resolution.

Accuracy in magneettisuusmittaus depends on calibration of magnetic field strength, temperature control, and correction for background signals. Magnetic hysteresis loops, obtained by sweeping the applied field, reveal key characteristics such as the coercive field and energy loss. These data are essential for designing magnetic alloys, optimizing magnetic recording media, and exploring novel phenomena like spin‑transfer torque and magnetic skyrmions.