C. G. Overberger

Ulrich, Robert D.

doi:10.1007/978-1-4684-2853-7_13

Cited by 4 publications

(5 citation statements)

References 182 publications

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“…However, the weak photoconductivity dependsalso on surface conductivity Ao according to (1) and in a similar way like in Fig. 10 for ho) = 3.4 ei- [12]. According to our model the drift mobility in the hulk is very low since the Fermi level is pinned by a high concentration of defects, siniilar t'o the pinning of the Fernii level at seniiconductor strrfaces hy a high densit'y of surface st'ates.…”

Section: Field Effect and Photoconductivitysupporting

confidence: 68%

Interpretation of surface phenomena on ZnO by the compensation model

Heiland

Köhl

1978

Phys. Stat. Sol. (a)

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Field effect mobility and surface photoconductivity on ZnO crystals increase for several orders of magnitude with dark surface conductivity (electron accumulation). An explanation was given previously: Only a small increasing fraction of the injected electrons appears in the conduction band whereas the main part is trapped by surface states. In the new compensation model the trapping action of the surface states is replaced by that of bulk defects changing their condition of charge within an accumulation layer during variations of band bending: From the temperature dependence of con ductivity and Hall effect a set of three bulk defect levels is evaluated. The same set is used for a newcalculation of the accumulation layer and for a quantitative interpretation of photoconductivity and field effect measurements. Also surface photovoltage and photolysis data are discussed. All these experimental results are obtained on single crystals bearing an accumulation layer. Properties of thin polycrystalline ZnO films are also treated. The concept of a drift mobility is of central importance for the compensation model. As a result of compensation space charge layers are much thinner than previously assumed.

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Section: Field Effect and Photoconductivitysupporting

confidence: 68%

Interpretation of surface phenomena on ZnO by the compensation model

Heiland

Köhl

1978

Phys. Stat. Sol. (a)

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“…First, the small J parameter (about 0.25eV) estimated from experiment suggests the possibility of strong canting or magnetic fluctuation at elevated temperature (100K). Second, the recent neutron experiment 25 on this compound actually suggests the existence of G-type spin canting and significant reduction of magnetic moment at 100K. Nevertheless, according to our calculations, to be able to reproduce the observed shape, substantial (more than 50 percent) mixture of low temperature phase is required.…”

Section: Yvo3 At Intermediate Temperature (77kmentioning

confidence: 68%

Anisotropic optical conductivities due to spin and orbital ordering inLaVO3andYVO3
Fang
¹
,
Nagaosa
²
,
Terakura³
2003
Phys. Rev. B
39
3
37
0
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The anisotropy of low energy (0∼5eV) optical excitations in strongly correlated transition-metal oxides is closely related to the spin and orbital orderings. The recent successes of LDA+U method in describing the magnetic and electronic structures enable us to calculate the optical conductivity from first-principles. The LaVO3 and YVO3, both of which have 3d 2 configuration and have various spin and orbital ordered phases at low temperature, show distinct anisotropy in the optical spectra. The effects of spin and orbital ordering on the anisotropy are studied in detail based on our first-principles calculations. The experimental spectra of both compounds at low temperature phases can be qualitatively explained with our calculations, while the studies for the intermediate temperature phase of YVO3 suggest the substantial persistence of the low temperature phase at elevated temperature.

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“…1 More recently, synthesis of even finer, nanosized particles has become important for synthesis of materials with unique properties and characteristics. 2 In these processes, it is important to develop the means for control of the product particle size and crystallinity.…”

Section: Corona-assisted Flame Synthesis Of Ultrafine Titania Particlesmentioning

confidence: 99%

Corona-assisted flame synthesis of ultrafine titania particles

Vemury

Pratsinis

1995

Applied Physics Letters

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Synthesis of ultrafine titania particles is investigated in a diffusion flame aerosol reactor in the presence of a gaseous electric discharge (corona) created by two needle electrodes. The corona wind flattens the flame and reduces the particle residence time at high temperatures, resulting in smaller primary particle sizes and lower level of crystallinity. Increasing the applied potential from 5 to 8 kV reduces the particle size from 50 to 25 nm and the rutile content from 20 to 8 wt %. Coronas provide a clean and simple technique that facilitates gas phase synthesis of nanosized materials with controlled size and crystallinity.

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C. G. Overberger

Cited by 4 publications

References 182 publications

Interpretation of surface phenomena on ZnO by the compensation model

Interpretation of surface phenomena on ZnO by the compensation model

Anisotropic optical conductivities due to spin and orbital ordering inLaVO3andYVO3
Fang
¹
,
Nagaosa
²
,
Terakura³
2003
Phys. Rev. B
39
3
37
0
View full text Add to dashboard Cite

Corona-assisted flame synthesis of ultrafine titania particles

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C. G. Overberger

Cited by 4 publications

References 182 publications

Interpretation of surface phenomena on ZnO by the compensation model

Interpretation of surface phenomena on ZnO by the compensation model

Anisotropic optical conductivities due to spin and orbital ordering inLaVO3andYVO3Fang1, Nagaosa2, Terakura3 2003Phys. Rev. B393370View full textAdd to dashboardCite

Corona-assisted flame synthesis of ultrafine titania particles

Contact Info

Product

Resources

About

Anisotropic optical conductivities due to spin and orbital ordering inLaVO3andYVO3
Fang
¹
,
Nagaosa
²
,
Terakura³
2003
Phys. Rev. B
39
3
37
0
View full text Add to dashboard Cite