The Effect of γ Irradiation on Phase Transitions in the Polyimide–YBa{sub 2}Cu{sub 3}O{sub 6+} {sub x} System

Journal Article · Fri Jun 15 00:00:00 EDT 2018 · Optics and Spectroscopy

DOI:https://doi.org/10.1134/S0030400X18060188· OSTI ID:22786412

Mukashev, K. M.; Kyrykbaeva, A. A. ^[1]

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1. Al-Farabi Kazakh National University (Kazakhstan)

The effect of γ irradiation on optical properties of films of the polyimide–YBa{sub 2}Cu{sub 3}O{sub 6.7} system with different concentrations of the filler in the form of the finely crystalline compound YBa{sub 2}Cu{sub 3}O{sub 6.7} (0.05 wt %, 0.10 wt %, and 0.50 wt %) has been investigated. The properties were studied on an IKS-29 infrared spectrophotometer in a spectral range of 400–4200 cm{sup –1} at room temperature. The samples were irradiated in air under room conditions on an RKhM-γ-20 by doses of 150, 250, and 600 kGy. The power of the exposure dose of the {sup 60}Co source was 0.16 rad/s. It has been established that irradiation with a dose of up to 600 kGy of the abovementioned system slightly affects the structure of the polyimide matrix but decreases the number of free radical groups in the film structure with the formation of hydrogen bonds. In the range of 400–4200 cm{sup –1} at D = 150 kGy, the most intense changes in spectra of polymeric composite samples have been revealed. In the range of 2850–3350 cm{sup –1}, the wide absorption spectrum band is preserved, which is caused by the presence of Cu, Y, and Ba crystallohydrates. The band is related to deformation vibrations of the Cu–O bond in YBa{sub 2}- Cu{sub 3}O{sub 6.7} (YBCO) chains due to properties of barium carbonate, formation of oxygen vacancies in the filler, and vibrations of the Cu(I)–O(I) bonds near one or several O(4) vacancies. Irradiation by doses of 250 and 600 kGy for different concentrations of the filler leads to a decrease in the signal intensity in the range of 1800–3600 cm{sup –1} by 20–35% on average. Peaks related to interband transitions (transitions of the Cu(I)–Cu(IY)–Cu(II) system) and bending vibrations O(I)–Cu(I) are not changed by strains of O(IY)–Cu(I) bonds. This testifies to the radiation-stimulated diffusion of oxygen atoms to O(IY) sites determining the orthorhombic phase of YBa{sub 2}Cu{sub 3}O{sub 6.7} from the occupied positions in the Cu–O sublattice.

• OSTI ID: 22786412
• Journal Information: Optics and Spectroscopy, Vol. 124, Issue 6; Other Information: Copyright (c) 2018 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0030-400X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
BARIUM OXIDES
COBALT 60
CONCENTRATION RATIO
COPPER OXIDES
DIFFUSION
ENERGY-LEVEL TRANSITIONS
FILMS
GAMMA RADIATION
HIGH-TC SUPERCONDUCTORS
IRRADIATION
OPTICAL PROPERTIES
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
PHYSICAL RADIATION EFFECTS
SPECTROPHOTOMETERS
YTTRIUM OXIDES