TY - JOUR
T1 - Magnetoimpedance, ferromagnetic resonance, and low field microwave absorption in amorphous ferromagnets
AU - Valenzuela, R.
AU - Zamorano, R.
AU - Alvarez, G.
AU - Gutiérrez, M. P.
AU - Montiel, H.
PY - 2007/4/15
Y1 - 2007/4/15
N2 - For many applications, the efficiency of giant magnetoimpedance (GMI) increases as the working frequency increases; the natural limit seems to be ferromagnetic resonance (FMR). However, MI is an essentially different phenomenon than FMR. The latter is a quantum-mechanical phenomenon which should satisfy the Larmor equation, while MI extends continuously from some hundreds of kHz up to the GHz range. A new phenomenon, which appears at very low fields in FMR experiments (by means of measurements around zero field that need a special accessory to compensate the remanence of electromagnets, and accurately measure very low magnetic fields) led to a clear difference between MI and FMR. This microwave interaction, which we call 'low field absorption' (LFA), has shown a strong similarity with MI, as far as it is also controlled by the anisotropy field. In this work, we show the start of the splitting between MI and FMR at frequencies ∼ 200 MHz, and the full differentiation between LFA and FMR at 9.4 GHz. We analyze the basic features of LFA and the conditions to be properly compared with GMI. Finally, we present some studies on selected materials.
AB - For many applications, the efficiency of giant magnetoimpedance (GMI) increases as the working frequency increases; the natural limit seems to be ferromagnetic resonance (FMR). However, MI is an essentially different phenomenon than FMR. The latter is a quantum-mechanical phenomenon which should satisfy the Larmor equation, while MI extends continuously from some hundreds of kHz up to the GHz range. A new phenomenon, which appears at very low fields in FMR experiments (by means of measurements around zero field that need a special accessory to compensate the remanence of electromagnets, and accurately measure very low magnetic fields) led to a clear difference between MI and FMR. This microwave interaction, which we call 'low field absorption' (LFA), has shown a strong similarity with MI, as far as it is also controlled by the anisotropy field. In this work, we show the start of the splitting between MI and FMR at frequencies ∼ 200 MHz, and the full differentiation between LFA and FMR at 9.4 GHz. We analyze the basic features of LFA and the conditions to be properly compared with GMI. Finally, we present some studies on selected materials.
KW - Amorphous metals, metallic glasses
KW - Microwave
UR - http://www.scopus.com/inward/record.url?scp=33947239850&partnerID=8YFLogxK
U2 - 10.1016/j.jnoncrysol.2006.12.113
DO - 10.1016/j.jnoncrysol.2006.12.113
M3 - Artículo
SN - 0022-3093
VL - 353
SP - 768
EP - 772
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 8-10
ER -