Characteristics of the magnetosensitive non-resonant power absorption of microwave by magnetic materials

Detection of the magnetic and electric transitions by electron paramagnetic resonance and low-field microwave absorption in the magnetoelectric Pb(Fe0.5Ta0.5)O3

“…LFMA lines show the absence of any irreversible microwave energy-absorption process in the ordered and disordered phases. This behavior contrasts strongly with the one shown by high-T c superconductors [16], ferrimagnetic [15] and ferromagnetic [17,21] materials.…”

“…H dc could be varied from 0 to 6000 G. EPR spectra are recorded while cooling the sample in the 120-300 K temperature range. The spectrometer is modified by connecting X and Y input voltmeters that in turn are connected to a PC enabling digital data acquisition [16].…”

“…LFMA response uses the same EPR spectrometer, adequately modified [16]. These measurements are performed using a Jeol ES-ZCS2 zero-cross sweep unit that digitally compensates any remanence in the electromagnet, allowing the measurements to be carried out by cycling H dc about their zero value, continuously of −1000 G ≤ H dc ≤ +1000 G; with a standard deviation of less than 0.2 G for the measured field.…”

“…Recently, we have implemented a technique to measure the non-resonant microwave absorption around zero magnetic field [16], which has been denominated as low-field microwave absorption (LFMA). This technique has recently been used to detect the magnetic transition in materials [12,15,17], and provide highly sensitive detection of magnetic order.…”

Low-field microwave absorption in pulse laser deposited FeSi thin film

“…For magnets and ferrites the LFMA signal is associated with the onset of the ordered phase and provides a sensitive detector of magnetic ordering [7,12,13]. For high-temperature superconductors LFMA signal reveals a change to superconductive state [6], while in semi-conductors the LFMA signal is due to magneto-resistive effects [13].…”