Mixed oxide ion and proton conduction and p-type semiconduction in BaTi0.98Ca0.02O2.98 ceramics

Ren, Pengrong; Masó, Nahum; Liu, Yang; Ma, Le; Fan, Huiqing; West, Anthony R.

doi:10.1039/c3tc00145h

Cited by 37 publications

(28 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…29 For example, it was shown that B-site acceptor (Ca) doped BaTiO 3 exhibited mixed conduction and the conductivity minima became increasingly flat as the Ca concentration increased. 33,34 This was attributed to an increase in the pO 2independent ionic conductivity. 34 In recent studies on nonstoichiometric and doped (Bi 1/2 Na 1/2 )TiO 3 (BNT), it was shown that for undoped, acceptor-doped and Bi-deficient BNT, oxygen vacancies dominated bulk conduction.…”

Section: Resultsmentioning

confidence: 99%

“…This finding is consistent with literature reports available on defect studies in perovskite ferroelectric ceramics . For example, it was shown that B‐site acceptor (Ca) doped BaTiO 3 exhibited mixed conduction and the conductivity minima became increasingly flat as the Ca concentration increased . This was attributed to an increase in the p O 2 ‐independent ionic conductivity .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

et al. 2016

View full text Add to dashboard Cite

Polycrystalline BaTiO3–Bi(Zn1/2Ti1/2)O3 (BT–BZT) ceramics have superior dielectric properties for high‐temperature and high‐energy density applications as compared to the existing materials. While it has been shown that the addition of BZT to BT leads to an improvement in resistivity by two orders of magnitude, in this study impedance spectroscopy is used to demonstrate a novel change in conduction mechanism. While nominally undoped BT exhibits extrinsic‐like p‐type conduction, it is reported that BT–BZT ceramics exhibit intrinsic n‐type conduction using atmosphere‐dependent conductivity measurements. Annealing studies and Seebeck measurements were performed and confirmed this result. For BT, resistivity values were higher for samples annealed in nitrogen as compared to oxygen, whereas the opposite responses were observed for BZT‐containing solid solutions. This suggests a fundamental change in the defect equilibrium conditions upon the addition of BZT to the solid solution that lowered the carrier concentration and changed the sign of the majority charge carrier. This is then also linked to the observed improvement in resistivity in BT–BZT ceramics as compared to undoped BT.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

et al. 2016

View full text Add to dashboard Cite

show abstract

“…There is no evidence for oxide ion conduction in the impedance data, although oxygen vacancy migration has been reported in other perovskite systems. 24,25,27,41 All samples showed a grain-boundary resistance which was larger than the bulk resistance. While grain-boundary resistances were also sensitive to dc bias, a larger effect was seen with the sample bulk resistances.…”

Section: Discussionmentioning

confidence: 97%

“…The capacitive model does not require the segregation of oxygen vacancies. There is no evidence for oxide ion conduction in the impedance data, although oxygen vacancy migration has been reported in other perovskite systems …”

Section: Discussionmentioning

confidence: 99%

Voltage‐Dependent Bulk Resistivity of SrTiO₃:Mg Ceramics

et al. 2014

Self Cite

View full text Add to dashboard Cite

Single phase ceramics of composition Sr(Ti1–xMgx)O3–x: 0 ≤ x ≤ 0.01 were prepared by sol–gel synthesis and characterized by X‐ray diffraction, scanning electron microscopy, impedance spectroscopy, and current–voltage measurements. The bulk and grain‐boundary conductivities increase on application of a small dc bias voltage in the range 3–200 V/cm and at temperatures in the range 150°C–800°C. A qualitatively similar increase in conductivity occurs on increasingPnormalO2 in the surrounding atmosphere, which shows that conduction is p type. The conductivity increase is reversible on removal of the dc bias or on reducing PnormalO2 and is not observed in undoped SrTiO3. It is an intrinsic property of the bulk material, differs from the voltage‐dependent effects observed with varistors and is attributed to changes in redox equilibria between oxygen species at the surface which cause changes in carrier concentration in the interior. A capacitive model of this low‐field dc bias effect is presented and compared with a memristive model of high field resistance degradation.

show abstract

“…In these cases, the main charge carriers are electron holes, leading to p-type semiconductivity. [57][58][59][60][61] The extrinsic holes are formed through the absorption of oxygen molecules on the surface of the sample, facilitated by the presence of oxygen vacancies.…”

Section: Electrical Propertiesmentioning

confidence: 99%

Oxygen deficient perovskites: effect of structure on electrical conductivity, magnetism and electrocatalytic activity.

Hona¹

View full text Add to dashboard Cite

Oxygen evolution reaction …………………………………………....19 CHAPTER 2. TRANSFORMATION OF STRUCTURE, ELECTRICAL CONDUCTIVITY AND MAGNETISM IN AA'Fe2O6-δ, A=Sr, Ca and A'= Sr..…... 21 Introduction ………………………………………………………………….. 21 Experimental ……... …………………………………………………………. 23 Results and discussion ………………………………………………………. 25 Crystal structure ……………………………………………………... 25 Magnetic structure …………………………………………………… 33 Electrical Properties ………………………………………………..… 36 Conclusion ………………………………………………………………...…. 43 CHAPTER 3. UNRAVELING THE ROLE OF STRUCTURAL ORDER IN TRANSFORMATION OF ELECTRICAL CONDUCTIVITY IN Ca2FeCoO6-δ, CaSrFeCoO6-δ and Sr2FeCoO6-δ …………………………………………………..….. 44 ix Introduction ………………………………………………………………...…. 44 Experimental ………………………………………………………………..…. 46 Results and discussion …………………………………….…………………. 48 Crystal structure ………………………………………….…………… 48 X-ray photoelectron spectroscopy …………………………………… 61 Electrical conductivities ……………………………………...………. 65 Conclusion …………………………………………………………………….. 73 CHAPTER 4. MAGNETIC STRIUCTURE OF CaSrFeCoO5 ………………..……… 75 Introduction …………………………………………………………….……….75 Experimental section ……………………………………………….………….. 77 Results and discussion ………………………………………………………….……. 78 Conclusion ……………………………………………………………….…………… 86 CHAPTER 5. ELECTRICAL PROPERTIES OF ORDERED OXYGEN-DEFICIENT PEROVSKITE Ca2Fe0.5Ga1.5O5…………..…..……………………………………….. 87 Introduction …………………………………………….……………………. 87 Materials and methods ………………………………….……………………. 90 Results and discussion ……………………………………...……….…………91 Crystal structure …………………………………………….….……… 91 x Electrical properties ………………………………..………….……… 94 Conclusion ……………………………………………..…………..…………. 99 CHAPTER 6. ENHANCED ELECTRICAL PROPERTIES OIN BaSrFe2O6-δ (δ=0.5): A DISORDERED DEFECT-PEROVSKITE………………………..………………..…. 100 Introduction …………………………………………………….…………… 100 Experimental……… ………………………………………..……………….. 102 Results and discussion …………………………………………..…………… 103 Crystal structure …………………………………………………...…. 103 Magnetic properties ………………………………………...…………109 Electrical properties ………………………………………………….. 111 Conclusion ……………………………………………….………………….. 115 CHAPTER 7. CHARGE-TRANSPORT PROPERTIES OF Ca2FeGaO6-δ AND CaSrFeGaO6-δ: THE EFFECT OF DIFECT-ORDERED .……………………...…….. 117 Introduction ………………………………………………………………….. 117 Experimental …………………………………………….………………….. 120 Results and discussion ………………………………..……………………… 121 Crystal structure ……………………………………………….…….. 121 Microstructure and X-ray photoelectron spectroscopy studies…………125 Electrical properties ………………………………….………………. 127 Conclusion ………………………………………………………..…………. 133 xi CHAPTER 8. DISPARITY IN ELECTRICAL AND MAGNETIC PROPERTIES OF ISOSTRUCTURAL OXYGEN-DEFICIENT PEROVSKITES BaSrCo2O6-δ AND BaSrCoFeO6-δ ………..………….……………………………………………..…….. 134 Introduction ……………………………………………………….…………. 134 Experimental……… …………………………………….….………………… Results and discussion …………………………………….……...………….. Crystal structure and crystallite morphology …….………….………… X-ray photoelectron spectroscopy (XPS) and iodometric titration ….…141 Magnetic properties ……………………………………………....…… Electrical conductiviti...

show abstract

Mixed oxide ion and proton conduction and p-type semiconduction in BaTi0.98Ca0.02O2.98 ceramics

Cited by 37 publications

References 25 publications

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

Voltage‐Dependent Bulk Resistivity of SrTiO₃:Mg Ceramics

Oxygen deficient perovskites: effect of structure on electrical conductivity, magnetism and electrocatalytic activity.

Contact Info

Product

Resources

About

Mixed oxide ion and proton conduction and p-type semiconduction in BaTi0.98Ca0.02O2.98 ceramics

Cited by 37 publications

References 25 publications

Conduction Mechanisms in BaTiO3–Bi(Zn1/2Ti1/2)O3 Ceramics

Conduction Mechanisms in BaTiO3–Bi(Zn1/2Ti1/2)O3 Ceramics

Voltage‐Dependent Bulk Resistivity of SrTiO3:Mg Ceramics

Oxygen deficient perovskites: effect of structure on electrical conductivity, magnetism and electrocatalytic activity.

Contact Info

Product

Resources

About

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

Conduction Mechanisms in BaTiO₃–Bi(Zn_1/2Ti_1/2)O₃ Ceramics

Voltage‐Dependent Bulk Resistivity of SrTiO₃:Mg Ceramics