X-RAY PHOTOEMISSION ELECTRON MICROSCOPE DETERMINATION OF ORIGINS OF ROOM TEMPERATURE FERROMAGNETISM AND PHOTOLUMINESCENCE IN HIGHCo-CONTENTCo_xZn_1-xOFILMS

Abstract

In this paper, we reported on the X-ray photoemission electron microscope (XPEEM) determination of magnetic and luminescence origins for two Co x Zn 1-x O films. The cobalt fraction x of radio frequency co-sputtered samples were 0.86(2) and 0.92(2), respectively. Films were ferromagnetic and semiconductive. Unique narrow green color lines beside the ZnO intrinsic emissions were found with a decay time in microsecond range at room temperature. Origins of magnetic and luminescence properties were determined with XPEEM. The X-ray absorption near edge structure at the Co L3-edge denoted that Co was partially oxidized, and phase-contrast images together with chemical composition identification further proved that Co and CoO co-existed in the samples. The ferromagnetism was attributed to ferromagnetism of Co clusters partially canceled by the antiferromagnetism of its oxide, and the photoluminescence to bound exciton in ZnO nanoclusters and defect related centers of ZnO nanoclusters in a Co -rich matrix. Present results show possibilities for adjusting magnetic and luminescence properties of Co – ZnO compounds by changing the cobalt concentration.

Metallic Contact between MoS2 and Ni via Au Nanoglue

“…The secondary electron signals through a multichannel plate were recorded for the total electron yields. More details of the measurements can be found in previous experiments …”

“…More details of the measurements can be found in previous experiments. [42] Photocatalytic Measurements: Degradation measurements were performed under UV light (UV lamp, 500 W) irradiation. During each measurement, (MoS 2 ) 92.9 Ni 4.2 Au 2.9 sample (50 mg) and MB (50 mL, 10 mg L −1 ) were mixed and then the suspensions were magnetically stirred in the dark for 30 min to eliminate the equilibrium effects before the irradiation.…”

Separation of valence states in thin films with mixed V2O5 and V7O16 phases

“…More details of the XPEEM experiment can be found, e.g. in [24]. Total electron yields (TEY) were recorded following tuning of the photon energy.…”

Introducing Magnetism into 2D Nonmagnetic Inorganic Layered Crystals: A Brief Review from First-Principles Aspects

“…On the TM-doped ZnO monolayer, intrinsic ferromagnetism was successfully introduced while the semiconductive structures were maintained [80]. A regionally excessive quantity of the dopants exceeded the solid solubility of the oxide thin films, which resulted in nodules on the films [81]. Such a phenomenon also exists when clusters interact with the ILC slabs [58].…”