Masao Sawada

Fine Structures of X-ray Absorption Spectra Of Cobalt in the Face Centered Cubic Lattice and Close-packed Hexagonal Lattice

Samples of cobalt of the α-modification (hexagonal close-packed lattice) and the β-modification (face centered cubic lattice) and their mixtures were prepared, and their crystal structures were examined by means of the X-ray diffraction method. Fine structures of the X-ray K absorption spectra of these cobalt samples were photographed by a bent crystal spectrograph and the mass absorption coefficients in the X-ray K absorption spectral region were measured by using the North American Philips Diffraction Unit and Wide Range Spectrometer modified to a tube spectrometer with a Geiger-Muller counter. By comparing these photometer curves of these spectrograms or the recorded curves, the fine structures of the absorption spectra of these cobalt samples were found to be very similar. The wavelength values and the mass absorption coefficient of the fine structures of the absorption spectra also nearly coincided within experimental errors, and thus the position and the form of the maximum and minimum of these stru...

Fine Structures of X-ray Absorption Spectra of Crystalline and Amorphous Germanium

The X-ray absorption spectra of crystalline and amorphous germanium were photographed and fine structures at the K absorption edges were observed to 500 ev. in the crystalline and to 350 ev. in the amorphous state. The shape of the fine structure of amorphous germanium is like that of crystalline germanium though the small fluctuations disappear and the energy values measured from the main edge are smaller than the values of corresponding absorption maxima and minima of the crystalline germanium. From the comparison of the fine structures of both states we suggest that a structure which is like the diamond lattice of crystalline Ge with the smaller spacing exists in the amorphous Ge and this result coincides with the result of analysis of the X-ray diffraction pattern by Richter.

Fine Structures of X-ray K Absorption Spectra of Copper in Various Copper Compounds

By using the North American Philips Diffraction Unit and Wide Range Goniometer modified to a tube spectrometer described by Coster and De Lang, the fine structures of the X-ray K absorption edges of copper in following compounds were recorded: cupric chloride (CuCl 2 ), cupric chloride dihydrate (CuCl 2 ·2 H 2 O), cupric bromide (CuBr 2 ), cupric sulfate pentahydrate (CuSO 4 ·5 H 2 O), cupric nitrate trihydrate (Cu(NO 3 ) 2 ·3 H 2 O), cupric carbonate (CuCO 3 ), cupric formate tetrahydrate (Cu(HCOO) 2 ·4 H 2 O), cupric acetate monohydrate (Cu(CH 3 COO) 2 ·H 2 O), bis glycino copper monohydrate (Cu(C 2 H 4 NO 2 ) 2 ·H 2 O), bis glycino copper hydrate (Cu(C 2 H 4 NO 2 ) 2 ·H 2 O), copper phthalocyanine β-form (CuC 32 H 16 N 8 ), copper phthalocyanine α-form (CuC 32 H 16 N 8 ), cuprous chrloride (CuCl), cuprous bromide (CuBr) and cuprous iodide (CuI). The recorded curves of the fine structures of the Cu K absorption edges of these compounds, except α- and β-phthalocyanine, were found to be very similar in fo...

On the Fine Structures of X-ray Absorption Spectra of Amorphous Substances The Amorphous State of the Binary System of Nickel-Sulfur. II.

We prepared the simultaneously electrodeposited Ni-S containing O, 9, 13, 17 and 25 wt. % sulfur and studied their crystalline forms and electrical resistances. Of these samples, those containing 9, 13 and 17% sulfur are amorphous and crystallize when heated to 180°C. The above results were reported in paper I. 1) We photographed the fine structures of Ni K X-ray absorption spectra in the amorphous and crystalline states of the same samples. We measured the wave-lengths of the fine structures of the Ni K absorption edge and intensities of their non-absorption maxima. We find the fine structures in the amorphous states; their shapes and wave-lengths show a similarity to those shown by the substances which have undergone crystallization. But generally, in the amorphous state, the fine structure is less pronounced at the shorter wave-length side than in the crystalline state. We conclude from the above results and previous results in paper I that the amorphous Ni-S is the aggregate state of fine crystals, an...

On the Amorphous State of the Binary System of Nickel-Sulfur

We prepared the simultaneously electro-deposited Ni-S containing 0, 9, 13, 17 and 25 wt. % sulfur and studied their crystalline forms by X-ray diffraction patterns. The diffraction patterns of Ni-S containing 13 and 17% S show a uniform fog, and 7% S shows a halo, and 0 and 25% S are the same as those of Ni and Ni 3 S 2 respectively. All amorphous samples crystallized after they had been heated to 180°C, and their diffraction patterns show the crystalline states of the two phase region of Ni and Ni 3 S 2 . The electrical resistances of these samples were measured in a vacuum furnace and in an oil bath. The resistances of these samples containing 9, 13 and 17% S gradually decrease as the temperature increases and suddenly drop at 180°C, then follow the usual behavior of the common metals for both increasing and decreasing temperatures. In the case of 0% S it does not differ from that of the pure nickel. We conclude that the amorphous state has the structure of a certain regularity, and that 180°C is the tr...

Absorption Coefficients of Fine Structures of X-ray Absorption Spectra at Various Absorber Thickness

By using the North American Philips Diffraction Unit and Wide Range Goniometer modified to a tube spectrometer described by Coster and De Lang, the fine structures of X-ray K absorption spectra of copper in metallic copper, CuCl 2 ·2H 2 O, CuSO 4 ·5H 2 O and cobalt in CoCl 2 ·6H 2 O at various thickness were measured. The structures near the absorption edges are affected by the absorber thickness. The mass absorption coefficients of maximum absorption jumps become large with decreasing absorber thickness, and the small maximum and ninimum near the absorption edges also become indistinct with increasing absorber thickness. The wavelengths of these structures are slightly affected. This is due to the finite resolving power of the spectrometer and the tail of the spectral window as mentioned by Parratt. In the high energy regions from the absorption edges the absorption coefficients are not affected by the absorber thickness.

On the Structure of the X-Ray Non-diagram Lines Kβη for Elements from Cr(24) to Zn(30)

With a bent crystal X-ray spectrograph of the Cauchois type, the nondiagram line K β η was resolved into two components and the longer wavelength one was designated as K β l line. The intensity ratios of the K β η and K β l to the K α 1 line were both estimated approximately to be the order of 10 -4 or less. On the basis of the wave-length positions, we could ascribe the origin of these lines to the two-electron jump between the double-hole levels (1 s 2 p ) and (2 s 3 s ). The hypothesis of such a two-electron jump which obeys the Heisenberg selection rule was first proposed by one of the present authors. 3) The K β η originates from the transition K L II – L I M I , and K β l from K L III – L I M I .

Source Scanning Type X‐Ray Grating Spectrometer

A method is proposed for designing an x‐ray spectrometer which can scan a limited wavelength region without movement of the concave grating or the electronic counter. Spectrometers widely used in the past have consisted of a fixed x‐ray source and a movable counter. This method is to use a fixed counter and a scanning x‐ray source to avoid undesirable movement of the sensitive electronic counter with its delicate and complex cooling system. The scanning x‐ray source will be obtained by scanning the cathode ray beam of an x‐ray tube. Two cases are analyzed theoretically; the Rowland circle (or Paschen‐Runge) mounting, and a new arrangement which will be designated as the Sawada mounting. In the latter, the concave grating and the middle point of the scanning region of the x‐ray source lie on the circumference of a circle with the same radius as that of the grating. It will be useful for constructing an x‐ray grating spectrometer in the future. The length of a spectral line is shorter in the case of the Saw...

On the Intensities of X-Ray Kα Satellites of Neon

The origin of K α satellites was generally believed to be one electron transition (1 s →2 p ) between doubly ionized states 1 s 2 s →2 s 2 p and 1 s 2 p →2 p 2 p . It was assumed that these ionizations take place due to, rather than formerly supposed direct collisions, the electron shake-off processes by a sudden change of the effective nuclear charge just after the ejection of K electron from the atom, which is subject to an impinging electron or X-ray photon. The ratio of the probabilities for occurrence of a 1 s 2 p state to 1 s 2 s state is calculated for neon by sudden approximation. On the other hand, by using the theory for the line strengths of multiplets and experimental data of X-ray spectra, this ratio is also computed. These two values coincide with each other, if a reasonable small value (almost zero) is chosen for the Coster-Kronig yield.

The Input Power Limit of the Cylindrical Rotating Anode of a X-ray Tube

The permissible maximum input power of the cylindrical anode of a continuous operating X-ray tube was calculated. Calculation was done for the cyclic dynamical steady state which was realized after sufficiently long continuous operation. This thermal problem was treated by DuMond as a one-dimensional problem in which heat flow was normal to the surface of the target. In our case a focus of an electron beam was a line focus and the width was small compared with the thickness of the target and the problem was treated as a two-dimensional problem containing transversal thermal flow.