Zero-field electron Larmor precession in NiFe/SiN/GaAs nanohybrid structure at room temperature

2018 ◽  
Vol 11 (6) ◽  
pp. 063003
Author(s):  
Kazuhiro Nishibayashi ◽  
Tadashi Kawazoe ◽  
Shin Saito ◽  
Tetsuji Mori ◽  
Hiroaki Fukuda
Keyword(s):  
Room Temperature ◽  
Zero Field ◽  
Larmor Precession ◽  
Field Electron

The EPR Zero-Field Splitting D and its Pressure and Temperature Dependence for Trigonal Mn2+ Centers in [Zn(H2O)6](BF4)2:Mn2+ Crystal

2006 ◽  
Vol 61 (5-6) ◽  
pp. 289-292 ◽  
Author(s):  
Hong-Gang Liu ◽  
Xiao-Xuan Wu ◽  
Wen-Chen Zheng ◽  
Lv He
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Coupling Mechanism ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Thermal Expansion Coefficients ◽  
Perturbation Formula ◽  
Expansion Coefficients

The EPR zero-field splitting D (= b02 ) and its pressure and temperature dependence for trigonal Mn2+ centers in low and room temperature phases in [Zn(H2O)6](BF4)2 :Mn2+ crystal are studied by a high-order perturbation formula based on the dominant spin-orbit coupling mechanism. From the studies, the local trigonal distortion angles, the local angular compressibilities and the local angular thermal expansion coefficients for Mn2+ centers in both phases of the [Zn(H2O)6](BF4)2 crystal are estimated. The results are discussed

scholarly journals Enhancement of zero-field skyrmion density in [Pt/Co/Fe/Ir]2 multilayers at room temperature by the first-order reversal curve

2020 ◽  
Vol 127 (22) ◽  
pp. 223901 ◽  
Author(s):  
Mangyuan Ma ◽  
Calvin Ching Ian Ang ◽  
Yong Li ◽  
Zizhao Pan ◽  
Weiliang Gan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Zero Field ◽  
First Order

scholarly journals Analytical treatment of cold field electron emission from a nanowall emitter, including quantum confinement effects

2010 ◽  
Vol 467 (2128) ◽  
pp. 1029-1051 ◽  
Author(s):  
Xi-Zhou Qin ◽  
Wie-Liang Wang ◽  
Ning-Sheng Xu ◽  
Zhi-Bing Li ◽  
Richard G. Forbes
Keyword(s):  
Electron Emission ◽  
Quantum Confinement ◽  
Field Electron Emission ◽  
Zero Field ◽  
Analytical Treatment ◽  
Thermodynamic Work ◽  
Field Electron ◽  
Quantum Confinement Effects ◽  
Occupied State ◽  
General Kind

An elementary approximate analytical treatment of cold field electron emission (CFE) from a classical nanowall (i.e. a blade-like conducting structure on a flat surface) is presented. This paper first discusses basic CFE theory for situations where quantum confinement occurs transverse to the emitting direction. It develops an abstract CFE equation more general than Fowler–Nordheim type (FN-type) equations, and then applies this to classical nanowalls. With sharp emitters, the field in the tunnelling barrier may diminish rapidly with distance; an expression for the on-axis transmission coefficient for nanowalls is derived by conformal transformation. These two effects interact to generate complex emission physics, and lead to regime-dependent equations different from FN-type equations. Thus: (i) the zero-field barrier height H R for the highest occupied state at 0 K is not equal to the local thermodynamic work-function ϕ , and H R rather than ϕ appears in equations; (ii) in the exponent, the power dependence on macroscopic field F M can be F −2 M rather than F −1 M ; (iii) in the pre-exponential, explicit power dependences on F M and H R differ from FN-type equations. Departures of this general kind are expected when nanoscale quantum confinement occurs. FN-type equations are the equations that apply when no quantum confinement occurs.

scholarly journals The Coordination Chemistry of Phosphoryl Compounds Containing the -N(CH3)2 Group, XII.

1973 ◽  
Vol 28 (3-4) ◽  
pp. 104-106 ◽  
Author(s):  
M.W.G. De Bolster ◽  
B. Nieuwenhuijse ◽  
J. Reedijk
Keyword(s):  
Electron Spin Resonance ◽  
Metal Ion ◽  
Room Temperature ◽  
Esr Spectroscopy ◽  
Hyperfine Coupling ◽  
Hyperfine Coupling Constant ◽  
Zero Field ◽  
Coupling Constant ◽  
Spin Resonance ◽  
Temperature Electron

Room temperature electron spin resonance powder spectra have been recorded for some compounds of the type Mn(ligand)p(anion)2 with hexamethylphosphoramide and nonamethylimidodiphosphoramide as ligands (p = 1 - 4) and BF-4, NO-3, Cl-, Br-, I- and NCS-as anions.The values for the zero-field parameters, D and λ, have been determined and are compared with literature data. It is shown that ESR spectroscopy can be very helpful in elucidating the structures of manganese(II) complexes.The high values for the hyperfine coupling constant of the solvates suggest that in these complexes the bonding between the ligands and the metal ion is essentially ionic.

scholarly journals Deposits of iron oxides in the human globus pallidus

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 291-298
Author(s):  
Helena Svobodová ◽  
Jana Hlinková ◽  
Pavol Janega ◽  
Daniel Kosnáč ◽  
Barbora Filová ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Human Brain ◽  
Iron Oxides ◽  
Globus Pallidus ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Point Of View ◽  
Zero Field ◽  
Fixed Temperature ◽  
Transmission Electron

Abstract Samples taken from the human brain (Globus Pallidus) have been investigated by physical techniques such as light microscopy, scanning electron microscopy, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. SEM-EDX/TEM investigation reveals multielemental composition of hematite and magnetite nanocrystals with sizes ranging from 40 nm to 100 nm and hematite microcrystals from 3 μm to 7 μm. Room temperature Mössbauer spectra show quadrupole doublets assigning to hematite and ferrihydrite. SQUID measurements of temperature dependence of the mass magnetic susceptibility between T = 2 – 300 K at DC field B0 = 0.1 T, the field dependence of the mass magnetization taken at the fixed temperature T0 = 2.0 and 4.6 K and the zero-field cooled and field cooled magnetization experiments (ZFCM/FCM) confirm a presence of ferrimagnetic phases such as maghemite and/or magnetite with hysteresis loops surviving until the room temperature. Differences between these measurements from the point of view of iron oxides detected can indicate important processes in human brain and interactions between ferritin as a physiological source of iron and surrounding environment.

scholarly journals Low-T magnetic anomaly in Ca2Fe2O5studied by single-crystal neutron diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1352-C1352
Author(s):  
Josie Auckett ◽  
Garry McIntyre ◽  
Maxim Avdeev ◽  
Hank De Bruyn ◽  
Chris Ling
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Temperature Interval ◽  
Diffraction Data ◽  
Room Temperature ◽  
Statistical Significance ◽  
Spin Reorientation ◽  
Careful Examination ◽  
Zero Field ◽  
Zone Method

Ca2Fe2O5, which belongs to the Brownmillerite family of promising solid-oxide fuel cell membrane materials, is an antiferromagnet (AFM) below TN = 720 K. A small ferromagnetic (FM) canting perpendicular to the AFM easy axis has previously been established by physical properties measurements, but never observed crystallographically. More intriguingly, it has been known for some time to display an anomalous elevation in magnetic susceptibility for 60 K < T < 140 K. [1] Based on measurements performed with small oriented single crystals, Zhou et al. [2] proposed that this anomaly was due to a reorientation of the spins from the crystallographic a axis to the c axis below 40 K, with a region of minimal magnetocrystalline anisotropy in the anomalous temperature interval. In order to test this, we grew a very large (~1 cm3) single crystal by the floating-zone method and collected neutron Laue diffraction data, against which we refined both the atomic and magnetic structures of Ca2Fe2O5 between 10 K and 300 K. We designed and built an ad hoc sample mount to apply a small (~35 Oe) magnetic field to the sample, ensuring perfect consistency with the magnetic susceptibility data, which were collected in a comparably small field. Our refinements against both zero-field and in-field diffraction data reproduce the G-type AFM structure of Ca2Fe2O5 excellently at room temperature, including the FM canting which we have refined to statistical significance for the first time. We can also show that in the intermediate temperature interval (T = 100 K), the spins are slightly less well-ordered due to competing sublattice interactions. However, careful examination of the data reveals that the material is still best described by the room-temperature magnetic structure at all measured temperatures – i.e., the spin-reorientation hypothesis is incorrect.

scholarly journals Pentacene in 1,3,5-Tri(1-naphtyl)benzene: A Novel Standard for Transient EPR Spectroscopy at Room Temperature

2021 ◽  
Author(s):  
Mirjam Schröder ◽  
Daniel Rauber ◽  
Clemens Matt ◽  
Christopher W. M. Kay
Keyword(s):  
Epr Spectroscopy ◽  
Room Temperature ◽  
Glass Transition Point ◽  
Zero Field ◽  
Microwave Resonator ◽  
Spectral Simulation ◽  
Zero Field Splitting ◽  
Standard Samples ◽  
Epr Spectrum ◽  
Data Set

AbstractTesting and calibrating an experimental setup with standard samples is an essential aspect of scientific research. Single crystals of pentacene in p-terphenyl are widely used for this purpose in transient electron paramagnetic resonance (EPR) spectroscopy. However, this sample is not without downsides: the crystals need to be grown and the EPR transitions only appear at particular orientations of the crystal with respect to the external magnetic field. An alternative host for pentacene is the glass-forming 1,3,5-tri(1-naphtyl)benzene (TNB). Due to the high glass transition point of TNB, an amorphous glass containing randomly oriented pentacene molecules is obtained at room temperature. Here we demonstrate that pentacene dissolved in TNB gives a typical “powder-like” transient EPR spectrum of the triplet state following pulsed laser excitation. From the two-dimensional data set, it is straightforward to obtain the zero-field splitting parameters and relative populations by spectral simulation as well as the $$B_{1}$$ B 1 field in the microwave resonator. Due to the simplicity of preparation, handling and stability, this system is ideal for adjusting the laser beam with respect to the microwave resonator and for introducing students to transient EPR spectroscopy.

Unraveling the Room-Temperature Spin Dynamics of Photoexcited Pentacene in Its Lowest Triplet State at Zero Field

2019 ◽  
Vol 123 (39) ◽  
pp. 24275-24279 ◽  
Author(s):  
Hao Wu ◽  
Wern Ng ◽  
Shamil Mirkhanov ◽  
Arman Amirzhan ◽  
Supamas Nitnara ◽  
...  
Keyword(s):  
Triplet State ◽  
Room Temperature ◽  
Spin Dynamics ◽  
Zero Field
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