Electron Paramagnetic Resonance Of Mn2 Research Articles

The Electron Spin Resonance of Mn2+ Ion in the Aqueous Solution of Surfactant

The Electron Spin Resonance of Mn2+ Ion in the Aqueous Solution of Surfactant

The electron spin resonance of Mn2+ in tremolite

The electron spin resonance of Mn2+ ion impurities in natural crystals of tremolite, 2(H2Ca2Mg5-(SiO3)8), was studied in the 9.2 GHz microwave frequency range, and at room temperature. The work was done on two crystals of tremolite containing different concentrations of Mn2+. In each case only one magnetic complex of Mn2+ was found. The resonance lines are characterized by a strong angular dependence of the line intensities, and this is coupled with the appearance of many forbidden lines of Mn2+. The resonance lines of the allowed transitions were fitted to a spin Hamiltonian of orthorhombic symmetry.

Electron Paramagnetic Resonance of Mn2± in K2SO4 Single Crystal

The paramagnetic resonance spectrum of divalent manganese ion in single crystals of potassium sulfate is described in detail over a large temperature range. Mn2± is found to substitute for K± and becomes associated with first-, second-, and third-neighbor potassium ion vacancies. The different spectra obtained at room temperature have been analyzed. Variation in the fine-structure spread with temperature has been studied for one of these spectra and the variation indicates a probable phase change at about − 130°C. This was supported by the observation that some of the resonance lines appear to begin to split into two as the temperature is lowered below − 130°C.

Electron paramagnetic resonance of Mn2+B in SrWO4

Electron paramagnetic resonance of Mn2+B in SrWO4

Electron paramagnetic resonance of Mn2+ in molybdates with the scheelite structure

Electron paramagnetic resonance of Mn2+ in molybdates with the scheelite structure

Paramagnetic resonance of Mn2+ in KNO3 single crystal: Motional effects

The electron paramagnetic resonance of Mn2+ in KNO3 single crystal is investigated over a temperature cycle through transition temperatures. The hyperfine coupling constant, A, half width,Δ H, and the line intensity, I, are found to show sudden changes at the transition temperature, at whichα-KNO3 changes intoβ-KNO3. The lines are much sharper in the high temperatureβ-phase than inα-phase of the crystal. They are explained, qualitatively, in terms of structure change and rotation of NO 3 − ions. The spectra in the two phases,α andβ, are analysed in terms of usual spin-Hamiltonian. A search of metastableγ-phase is also made and probable indications for the same are found.

The electron paramagnetic resonance of Mn2+ in SrMoO4

The electron paramagnetic resonance of Mn2+ in SrMoO4

Electron spin resonance of Mn2+ in NaCl single crystal and lattice defects

The electron spin resonance spectra of Mn2+ in NaCl single crystals are investigated in detail. Seven different spectra (I, II, III1, III2, IV, V and VI) are observed. The spectra I–IV are the same as those observed by earlier workers, while the spectra V and VI are observed here for the first time. The local symmetry at the paramagnetic ion is orthorhombic for the spectra IV and V and tetragonal for the spectrum VI about the crystallographic [001] direction. The properties of the spectrum IV are explained in terms of an associated pair Mn2+: O2 2− with O2 2− molecular ion at the nearest neighbour anion site in the [001] direction with its internuclear axis in the (001) plane. The spectrum V is assigned to the associated pair Mn2+: O2 2− coupled with a nearby cation vacancy in the [001] direction and the spectrum VI to Mn2+ ion associated with OH− ion at the anion site in the [001] direction with a probable second neighbour cation vacancy. All the observed spectra are analysed in terms of the parameters of the usual spin-Hamiltonian.

Forbidden hyperfine transitions in electron spin resonance of Mn2+ in NaCl single crystal

Forbidden hyperfine transitions are observed in the electron spin resonance spectrum of divalent Mn55 ion in NaCl single crystal for a particular associated pair. From the measurements of the M = + 1/2 → −1/2, Δm = ± 1 transitions the parametersQ′ and Q″ of the nuclear electric quadrupole part of the spin-Hamiltonian Ho = Q′ [Iz2 − 1/3 I (I + 1)] + Q″ (Ix2−Iy2) are found to be + 1.70 × 10−4 cm.−1 and +0.16 × 10−4 cm.−1 respectively.

“Forbidden” Transitions in the Electron Spin Resonance of Mn2+ in BaTiO3 Single Crystal

“Forbidden” Transitions in the Electron Spin Resonance of Mn²⁺ in BaTiO₃ Single Crystal

Electron paramagnetic resonance of Mn ++ in CdS : M.F. Deygen, V.M. Majevsky, V.J. Zevin and N.I. Vitrikhovsky (Vol. 6, No. 9, pp. 2756–2761).

Determinar a validade e confiabilidade intra e interavaliadores da utilização de cronômetros e vídeos para registro do tempo de execução do Line Drill Test (LDT), comparando‐as a fotocélula.Vinte e dois atletas universitários de basquetebol e handebol executaram o LDT em uma única tentativa. O tempo de execução foi registrado simultaneamente por fotocélula (padrão‐ouro) e avaliadores com cronômetros manuais. Simultaneamente, o teste foi filmado para posterior análise por avaliadores cegados com relação aos demais tempos obtidos. Foram determinados os seguintes índices: a) coeficiente de correlação intraclasse; b) coeficiente de variação; c) máxima diferença absoluta para um mesmo teste; e d) erro típico.Não houve diferença estatística no uso dos equipamentos. As correlações interavaliador e entre os equipamentos foram elevadas (r = 0.993 a r = 1.000; p < 0.001 para todas). Os índices entre cronômetros e fotocélulas foram: coeficiente de correlação intraclasse = 0.995 (p < 0.001), % coeficiente de variação = 0.85%, máxima diferença absoluta = 1.08 s e erro típico = 0.13 s; e entre vídeos e fotocélulas foram: coeficiente de correlação intraclasse = 0.999 (p < 0.001), % coeficiente de variação = 0.60%, máxima diferença absoluta = 0.52 s e erro típico = 0.07 s.Os resultados sugerem que a utilização de equipamentos de baixo custo (cronômetros e câmeras) para registrar o tempo de execução do LDTé válida e confiável.Determinar la fiabilidad y la validez de la medición del tiempo del Line Drill Test, obtenido a través de cronómetros y análisis de vídeo, comparándolas con fotocélula.Veintidós deportistas universitarios jugadores baloncesto y balonmano ejecutaron el Line Drill Test una sola vez. El tiempo de ejecución fue registrado simultáneamente mediante un sistema de fotocélula («gold‐stándar») y por evaluadores con cronómetros manuales. La prueba también fue grabada en vídeo para su posterior análisis por evaluadores ajenos a los resultados anteriores. Se determinaron los siguientes índices: a) coeficiente de correlación intraclase, b) coeficiente de variación, c) máxima diferencia absoluta para un mismo test y d) error estándar.No hubo diferencias estadísticas con el uso de los diferentes equipos. Las correlaciones interexaminadores y entre los equipos fueron altas (r = 0.993 a r = 1.000; p < 0.001 para todas). Los índices entre cronómetros y fotocélulas han sido: coeficiente de correlación intraclase = 0.995 (p < 0.001), % coeficiente de variación = 0.85%, máxima diferencia absoluta = 1.08 s, y error estándar = 0.13 s, y entre vídeos y fotocélulas han sido: coeficiente de correlación intraclase = 0.999 (p < 0.001), % coeficiente de variación = 0.60%, máxima diferencia absoluta = 0.52 s, y error estándar = 0.07 s.Los resultados sugieren que el uso de equipos de bajo coste (cronómetros y cámaras) para los registros de tiempo de la prueba del Line Drill Test, es válido y fiable.To ascertain the validity and reliability of intra and inter evaluators of the use of stopwatches and videos in order to record the runtime of Line Drill Test compared to a photocell system.22 academic basketball and handball players performed the Line Drill Test in a single attempt. Photocells (gold standard) and evaluators with manual stopwatches recorded the runtime of the Line Drill Test simultaneously. At the same time, the test was videotaped in order to be analyzed by blinded evaluators. The following indexes were calculated: a) intraclass correlation coefficient, b) coefficient of variation, c) maximum absolute difference in the same test and d) typical error.there were no differences among equipment. Evaluators and equipments showed high and positive correlation (r = 0.993 to r = 1.000; p < 0.001 for all). The indexes between stopwatches and photocells were intraclass correlation coefficient = 0.995 (p < 0.001), coefficient of variation % = 0.85%, maximum absolute difference = 1.08 s and typical error = 0.13 s; and the indexes between videos and photocells were: intraclass correlation coefficient = 0.999 (p < 0.001), coefficient of variation % = 0.60%, maximum absolute difference = 0.52 s and typical error = 0.07 s.the use of the low cost equipment (manual stopwatches and cameras) to measure the runtime of the Line Drill Test are both valid and reliable resources.

Electron Spin Resonance of Mn2+ in BaTiO3

Electron Spin Resonance of Mn²⁺ in BaTiO₃

Electron paramagnetic resonance of Mn 2+ in apatite

On the basis of an analysis of the instability of drift caused by density and magnetic field inhomogeneities in plasmas with finite β, the effect of the instability on the excitation of kinetic Alfven wave (KAW) is probed. In the kinetic theory, which correctly treats the effect of the finite Larmor radius and the wave-particle resonant interaction, the motion of the ions is described with the Vlasov equation and the motion of electrons, with the kinetic drift equation. Comparing the effects by inhomogeneities in the density and in the magnetic field in plasmas with finite β, we found that the drift instability is more easily excited by the former, and in the instability so excited, the energy transfer is more intense. This energy transfer provides the physical basis for the excitation of KAW. As shown by numerical solutions, KAWs can be widely excited and produced in the magnetosphere, especially in the cusp of the magnetosphere, in the magnetopause and in the boundary layers of plasma sheets, where inhomogeneities are obvious. The results of the present work further illustrate that the KAW plays an important role in the energy transfer in magnetospheric regions.

"Forbidden" Hyperfine Transitions in the Electron Paramagnetic Resonance ofMn++in Cubic MgO

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Magnetic Resonance of Mn2+-Doped LiF Crystals

The electron paramagnetic resonance of Mn2+ in powdered LiF was observed at X-band and room temperatures for various impurity concentrations. The highest concentration was examined at K-band and low temperatures to obtain additional information regarding the distribution of Mn2+ ions which were introduced chemically into the lattice in small amounts. In the highest concentration, the K-band spectra indicate that part of the Mn2+ goes into the powder in the form of clusters of Mn and F which are antiferromagnetic at helium temperatures. NMR linewidth measurements on the lithium nuclei at low temperatures are qualitatively explained by the antiferromagnetism. The room-temperature data from the more dilute samples exhibit not only the expected hyperfine splitting but also a superhyperfine splitting. The hyperfine interaction of the Mn2+ ion was determined to be A55=90±2×10—4 cm—1, and the isotropic part of the superhyperfine interaction with each of the six fluorine nearest-neighbor nuclei was measured to be As=17.1±0.5×10—4 cm—1. Comparisons between K-band spectra from chemically prepared powdered samples and single crystals grown from the melt indicate that the melt method is unsuitable for obtaining the solid solution required to examine the superhyperfine spectra.

Forbidden lines in the hyperfine spectrum of the electron paramagnetic resonance of Mn++ in BaTiO3

The hyperfine spectrum of Mn++ in powder BaTiO3 was studied at 8740 MHz andT=80°K. The measured lines appearing as doublets between the hyperfine lines of Mn++ are explained as forbidden transitions of the typeΔM=±1,Δm=±1. A theoretical expression for the position of these doublets is given and some of the constants of the spin Hamiltonian are determined:g=2.001±0.001, ¦A¦=86 Oe,D ∼ 40 Oe.

The Electron Paramagnetic Resonance of Mn2+ Ions Surrounded by an Octahedron of Fluorine Ions

The measurements of the EPR of Mn 2+ ions as dilute, substitutional impurities in the single crystals of KMgF 3 , KCdF 3 , KCaF 3 , K 2 MgF 4 and NaMgF 3 were made. An X-ray examination revealed that divalent metal ions in these crystals were surrounded by an octahedron of six fluorine ions. The F 19 “super-hfs” superimposed on the usual hfs of Mn 55 has been observed. The dependence of the F 19 hf interaction constant ( A s ) upon the Mn 2+ –F - distance has been noticed and discussed. The A s in KMnF 3 has been estimated to be somewhat smaller than 16.7×10 -4 cm -1 .