arXiv subjects

Y. Guan

Publications and source records attributed to Y. Guan.

93 records · Page 6Linked to original sources

arXiv2009

A compact apparatus for studies of element and phase-resolved ferromagnetic resonance

We present a compact sample holder equipped with electromagnets and high frequency transmission lines; the sample holder is intended for combined x-ray magnetic circular dichroism (XMCD) and ferromagnetic resonance measurements (FMR). Time-resolved measurements of resonant x-ray detected FMR during forced precession are enabled by use of a rf excitation that is phase-locked to the storage ring bunch clock. Several applications of the combined XMCD + FMR technique are presented, demonstrating the flexibility of the experimental design.

cond-mat.mes-hall↗

arXiv2006

Weakly Coupled Motion of Individual Layers in Ferromagnetic Resonance

We demonstrate a layer- and time-resolved measurement of ferromagnetic resonance (FMR) in a Ni81Fe19 / Cu / Co93Zr7 trilayer structure. Time-resolved x-ray magnetic circular dichroism has been developed in transmission, with resonant field excitation at a FMR frequency of 2.3 GHz. Small-angle (to 0.2 degree), time-domain magnetization precession could be observed directly, and resolved to individual layers through elemental contrast at Ni, Fe, and Co edges. The phase sensitivity allowed direct measurement of relative phase lags in the precession oscillations of individual elements and layers. A weak ferromagnetic coupling, difficult to ascertain in conventional FMR measurements, is revealed in the phase and amplitude response of individual layers across resonance.

cond-mat.mtrl-sci↗

arXiv2006

Time-domain measurement of driven ferromagnetic resonance

We present a time-resolved measurement of magnetization dynamics during ferromagnetic resonance (FMR) in a single layer of Ni81Fe19. Small-angle (<1 deg.) precession of elemental Ni, Fe moments could be measured directly and quantitatively using time-resolved x-ray magnetic circular dichroism (XMCD) in transmission. The high temporal and rotational sensitivity of of this technique has allowed characterization of the phase and amplitude of driven FMR motion at 2.3 GHz, verifying basic expectations for a driven resonance.

cond-mat.mtrl-sci↗