Internal friction and electrical conductivity of phosphate glass with two TM oxides

Chomka, W.; Samatowicz, D.; Gzowski, O.; Murawski, L.

doi:10.1016/0022-3093(81)90100-9

Cited by 22 publications

(3 citation statements)

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“…During high temperature melting of the glasses with Fe 2 O 3 in air some Fe 2ϩ ions are formed along with Fe 3ϩ as in the case of Bi 2 O 3 -Fe 2 O 3 and similar other glasses prepared with Fe 2 O 3 and studied earlier. [24][25][26][27] Some Fe 2ϩ ions are also produced following the reaction Cu 1ϩ ϩFe 3ϩ →Fe 2ϩ ϩCu 2ϩ . The concentration of the Fe 2ϩ and the total iron ion concentrations (Fe t ) were measured chemically by titration of the acid ͑dilute HCl͒ solution of the glasses.…”

Section: Methodsmentioning

confidence: 99%

“…15,23 Therefore, the study of the transport properties of these multicomponent TMO glasses with two transition metal ions ͑Fe and Cu͒ would be interesting similarly to those of nonmagnetic Pb and Li doped glasses. 11,15 Earlier studies on the Fe containing semiconducting glasses [24][25][26][27] indicate the presence of Fe 2ϩ and Fe 3ϩ and the semiconducting behavior in the TMO glasses occurs due to the polaron hopping between the mixed valence states ͑Fe 2ϩ and Fe 3ϩ in particular͒.…”

Section: Introductionmentioning

confidence: 98%

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Structural and transport properties of (Bi,Pb)4Sr3Ca3Cu4−mFemOx (m=0–0.06) glasses: Precursors for high Tc superconductors

Chatterjee

Bhattacharya

Chaudhuri

1998

The Journal of Chemical Physics

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Microstructure and transport properties (between 80–450 K) of the Fe doped as-quenched Bi3Pb1Sr3Ca3Cu4−mFemOx (m=0.0, 0.02, 0.04, 0.05, and 0.06) type multicomponent glassy precursors for high-temperature superconductors were first reported in this paper. It has been shown from x-ray diffraction, scanning electron microscopy, thermal analysis, density, and oxygen molar volume measurements that single phase homogeneous glasses are formed. Even with small addition of Fe, a large change of glass transition temperature (Tg) indicates appreciable change of glass network structure of the undoped (Bi,Pb)4Sr3Ca3Cu4Ox glass which is reflected in the properties of the corresponding high-temperature annealed glass termed as glass-ceramic (GC) samples. These GC samples are found to be superconductors. Addition of Fe is considered to break up some of the original Cu–O–Cu bonds forming some new Cu–O–Fe and Fe–O–Fe type bonds. A nonlinearity (increase) in the dc conductivity (σdc) of the as-quenched glass sample is observed around m=0.02. This increase of dc conductivity is ascribed to be due to the additional hopping between Fe2+ and Fe3+ which finally destroys superconductivity for m⩾0.06. This is also responsible for the nonlinear variation of activation energy of the Fe doped glass and hence change in the superconducting properties of the glass ceramics. The high temperature (above θD/2, θD being the Debye temperature) σdc data of the glasses were explained by considering small polaron hopping conduction mechanism. The dc conductivity of these glasses are found to follow Greaves’ variable range hopping model in the intermediate range of temperature. The polaron hopping model of Schnakenberg and Emin can predict the conductivity data in the high-temperature regime. All the Fe-doped glass ceramics showed superconducting transitions with Tc between 100 and 110 K. The corresponding zero resistance temperature, Tco which is maximum (79 K) for m=0, decreases consistently with increase of Fe-concentration and finally superconducting behavior is destroyed for m⩾0.06. This behavior is consistent with-pair breaking mechanism.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Structural and transport properties of (Bi,Pb)4Sr3Ca3Cu4−mFemOx (m=0–0.06) glasses: Precursors for high Tc superconductors

Chatterjee

Bhattacharya

Chaudhuri

1998

The Journal of Chemical Physics

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“…Sayer and Lynch [3], Caley and Murthy [4], Bogomolova et al [5] and Chomka et al [6] all reported an initial decrease and then an increase in conductivity, whereas Bogomolova and Glassova [8] and Singh [9] reported an initial increase and then a decrease in conductivity, when one TM oxide is replaced by other TM oxides in glasses. They have suggested [4,6,7,9] that the increase of conductivity may be due to the hopping of electrons between TM ions of the different elements in addition to the hopping of electrons between TM ions of the same element. The decrease in electrical conductivity was suggested as due to the decrease of the redox ratio [4] and also to the possible formation of bridge bonds composed of one ion from each TM ion with one oxygen ligand, as a result of which hopping is inhibited.…”

Section: Introductionmentioning

confidence: 94%

Electrical conduction in copper phosphate glasses containing nickel or cobalt

Harani

Hogarth

1986

J Mater Sci

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A variation in d.c. conductivity and activation energy of 35 mol % CUO-65 mol % PzO~ glasses is observed as CuO is gradually replaced by NiO or CoO. These results are believed to be due to the change in the redox ratio of the two transition metal oxide glasses, which causes an increase and then a decrease of polaron hopping transitions between the ions of the same element and between the ions of the different transition metal elements.

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