Effect of the particle size on the microwave absorption in the Yttrium-iron garnet

A comparative study between micropowders and nanopowders of Y ₃Fe₅O₁₂ (YIG) by means of ferromagnetic resonance (FMR) is reported. Significant changes in lineshape of the FMR spectra between both samples are observed, in particular, the absorption mode in nanopowders have an internal structure which can be associated with magnetostatic modes. Additionally, a method to measure the non-resonant microwave absorption, as function of an applied magnetic field around zero field, known as the low-field microwave absorption (LFMA) is also employed. LFMA technique is used to give a further knowledge on the YIG samples, showing their main characteristics highlighted. These techniques are powerful tools for the research of magnetic materials at microwave frequencies.