scholarly journals Universal field-tunable terahertz emission by ultrafast photoinduced demagnetization in Fe, Ni, and Co ferromagnetic films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lin Huang ◽  
Sang-Hyuk Lee ◽  
Seon-Dae Kim ◽  
Je-Ho Shim ◽  
Hee Jun Shin ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Magnetic Hysteresis ◽  
Hysteresis Curve ◽  
External Fields ◽  
Terahertz Emission ◽  
Emission Signal ◽  
Ferromagnetic Films ◽  
Initial Magnetization ◽  
Emission Behavior ◽  
Magnetic Hysteresis Curve

Abstract We report a universal terahertz (THz) emission behavior from simple Ni, Fe, and Co metallic ferromagnetic films, triggered by the femtosecond laser pulse and subsequent photoinduced demagnetization on an ultrafast time scale. THz emission behavior in ferromagnetic films is found to be consistent with initial magnetization states controlled by external fields, where the hysteresis of the maximal THz emission signal is observed to be well-matched with the magnetic hysteresis curve. It is experimentally demonstrated that the ultrafast THz emission by the photoinduced demagnetization is controllable in a simple way by external fields as well as pump fluences.

Measurements of the Spin-Selective Magnetic Hysteresis Curve in Fe–3 wt.% Si Alloy Using Magnetic Compton Scattering

2018 ◽  
Vol 48 (3) ◽  
pp. 1456-1460
Author(s):  
Chan Wook Kim ◽  
Hee Soo Kang ◽  
Kyu Seok Han ◽  
Naruki Tsuji ◽  
Yoshiharu Sakurai
Keyword(s):  
Compton Scattering ◽  
Magnetic Hysteresis ◽  
Hysteresis Curve ◽  
Magnetic Hysteresis Curve

Sensing Creep Evolution in 410 Stainless Steel by Magnetic Measurements

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Alberto Polar ◽  
J. E. Indacochea ◽  
M. L. Wang
Keyword(s):  
Stainless Steel ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Magnetic Domain ◽  
Ferromagnetic Material ◽  
Hysteresis Curve ◽  
Nondestructive Examination ◽  
Creep Time ◽  
Ferromagnetic Steel ◽  
Magnetic Hysteresis Curve

The creep evolution was followed by conducting magnetic measurements on ferromagnetic steel samples exposed to different creep strains at a constant temperature. 410 stainless steel (410 SS) rods were submitted to creep at 625°C applying a constant stress of 124 MPa for different creep times. A magnetic hysteresis curve was generated for every sample. It was found that the shape of the hysteresis curves varied with creep time. The extent of creep was assessed by measuring magnetic saturation, coercivity, and remanence. The changes in microstructure due to creep are related to variations in magnetic properties, which are explained in terms of possible magnetic domain pinning. It was observed that the microstructural changes due to creep are better correlated with the coercivity of the material. In summary, it is feasible to use a magnetoelastic sensor to detect the partial level of creep in a ferromagnetic material by nondestructive examination.

Laser pulse induced efficient terahertz emission from Co/Al heterostructures

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Hui Zhang ◽  
Zheng Feng ◽  
Jine Zhang ◽  
He Bai ◽  
Huaiwen Yang ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Terahertz Emission

scholarly journals Room Temperature Ferromagnetism of (Mn,Fe) Codoped ZnO Nanowires Synthesized by Chemical Vapor Deposition

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yongqin Chang ◽  
Pengwei Wang ◽  
Qingling Sun ◽  
Yongwei Wang ◽  
Yi Long
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Chemical Vapor ◽  
Zno Nanowires ◽  
Hysteresis Curve ◽  
Chemical Vapor Deposition Method ◽  
Near Band Edge ◽  
Band Edge Emission

(Mn,Fe) codoped ZnO nanowires were synthesized on silicon substrates in situ using a chemical vapor deposition method. The structure and property of the products were investigated by X-ray, electron microscopy, Raman, photoluminescence, and superconducting quantum interference device magnetometer. The doped nanowires are of pure wurtzite phase with single crystalline, and the elements distribute homogeneously in the doped nanowires. Photoluminescence spectrum of the doped nanowires is dominated by a deep-level emission with a negligible near-band-edge emission. The magnetic hysteresis curve with a coercive field of 35 Oe is clearly observed at 300 K, resulting from room-temperature ferromagnetic ordering in the (Mn,Fe) codoped ZnO nanowires, which has great potential applications for spintronics devices.

scholarly journals Effect of sintering temperature on structural, magnetic, dielectric and optical properties of Ni–Mn–Zn ferrites

2021 ◽  
Author(s):  
Nazia Khatun ◽  
Mohammad Sajjad Hossain ◽  
Most. Hosney Ara Begum ◽  
Suravi Islam ◽  
Nazmul Islam Tanvir ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Spinel Ferrite ◽  
Magnetic Hysteresis ◽  
Dielectric Behavior ◽  
Hysteresis Curve ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Dielectric And Optical Properties ◽  
Wavenumber Region ◽  
Magnetic Dielectric

Spinel ferrite Ni[Formula: see text]Mn[Formula: see text]Zn[Formula: see text]Fe2O4 was prepared by a conventional ceramic process followed by sintering at three different temperatures (1050[Formula: see text]C, 1100[Formula: see text]C and 1150[Formula: see text]C). X-ray diffraction (XRD) investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm[Formula: see text] to 400 cm[Formula: see text]. Surface morphology showed highly crystalline grain development with sizes ranging from 0.27 [Formula: see text]m to 0.88 [Formula: see text]m. The magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity ([Formula: see text] and saturation magnetization ([Formula: see text]. Temperature caused a decrease in DC electrical resistivity, while the electron transport increased, suggesting the semiconducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were determined. The values of Curie temperature ([Formula: see text] and activation energy were influenced by the sintering temperature. Frequency-dependent dielectric behavior (100 Hz–1 MHz) was also analyzed, which may be interpreted by the Maxwell–Wagner-type polarization. The UV–vis–NIR reflectance curve was analyzed to calculate the bandgap of ferrites, which showed a decreasing trend with increasing sintering temperature.

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