Doping Concentration Regulates the Optical and Magnetic Properties of Twinned Crystal Cu_2–xEu_xO

Abstract

Twinned crystals of Cu2–x Eu x O were fabricated through a gas–liquid reaction and collaborative thermal annealing method. The effective doping of the europium (Eu) atoms in twinned crystal Cu2O is attributed to the mechanisms of ion diffusion and capture doping. To better investigate the room-temperature ferromagnetism (RTFM) of twinned crystal materials, further analysis was performed on the ferromagnetic properties of Cu2–x Eu x O bulk using field-cooling and zero-field-cooling measurements. The magnetic properties of the twinned crystal Cu2O mainly arise from the electronic spin polarization on the (111) twinned crystal plane. Furthermore, the parabolic characteristics of its saturation magnetization can be explained by two competing mechanisms present in the doping process. To investigate the magnetic origin of the twinned crystal Cu2–x Eu x O bulks, the spatial distribution of spintronic state density was analyzed using four distinct structural models. The results indicate that Eu atoms mainly contribute to the magnetism of the Cu2–x Eu x O bulks. The linkage between 4f electron-associated spin-polarized states and carriers in the twinned crystal Cu2–x Eu x O bulks makes them promising for spintronics applications.

Stair-Structured Cu2–xHoxO Materials with Adjustable Optical and Magnetic Properties

“…The red shift phenomenon is due to the fact that Ho 3+ ions entering the crystal lattice of the Cu 2 O structure reduced the number of Cu vacancies in the crystal. With the increase of Ho 3+ ion doping concentrations, Cu + ions are replaced by Ho 3+ ions and reduce the number of Cu + –Cu + vacant pairs in the gap of the crystal, which eventually leads to the blue shift phenomenon at high doping concentrations …”

“…Rare earth ions have been widely used in the fields of medical imaging, magnetoelectricity, and photoelectricity owing to their outstanding magnetic properties and PL properties. − Cu 2 O with a unique stair structure can be used as a matrix material for LED fluorescence slices and spintronic devices. − Trivalent rare earth ions, owing to their partially filled 4f inner shell, demonstrate exceptional absorption and fluorescence spectra . The appearance of sharp, line-like bands in their emission or excitation spectra is attributed to forbidden f–f transitions, resulting in high color purity in the emitted light.…”