Publisher Summary The chapter presents a study on relations between the concentrations of imperfections in crystalline solids. Many properties of crystalline solids, such as the electronic or ionic conductivity, the color, the luminescence, and the magnetic susceptibility are determined by the presence of imperfections. Generally, six types of primary imperfections are distinguished; namely phonons, electrons and holes, excitons, vacant lattice sites and interstitial atoms or ions, foreign atoms or ions in either interstitial or substitutional positions, and dislocations. In addition atoms of the base crystal may be present at lattice sites normally occupied by other atoms. Five types of primary imperfections—namely, electrons and holes, vacant lattice sites, interstitials, misplaced lattice atoms, and foreign atoms—are discussed in this chapter. The chapter presents a new treatment of these problems by making use of a graphical representation. This treatment, together with the use of a band scheme for the electronic energy levels, greatly facilitates the application of the theory and the deduction of conclusions from it. Apart from a few exceptions, binary nonmetallic compounds of the formula M X will be considered almost exclusively. Here M indicates an element of a more electropositive character (metal) and X an element of a more electronegative character.

Relations between the Concentrations of Imperfections in Crystalline Solids

Oxide ion conducting solid electrolytes based on Bi2O3

As one of the most prevalent metal oxides on Earth, iron oxide, especially α-Fe2O3 or hematite, has been the subject of intense research for several decades. In particular, the combination of a relatively small bandgap and related visible light absorption, natural abundance, low cost, and stability under deleterious chemical conditions has made it ideal for many potential applications. However, the short charge carrier lifetime or diffusion length has limited its applicability. Nanostructures of hematite offer the possibility of overcoming some of the limitations through control of the structures and thereby its optical and electronic properties. In this review, we provide an overview of recent progress on the synthesis and characterization of nanostructured hematite, with an emphasis on the charge carrier dynamics and photoelectrochemical properties. Both current challenges and future opportunities are also discussed.

Nanostructured hematite: synthesis, characterization, charge carrier dynamics, and photoelectrochemical properties

An immunochemical assay device comprising a base member, an array disposed on the base member, and at least one assay indicia zone. The array comprises (i) a reservoir pad to receive sample liquid, (ii) a wicking membrane, and (iii) at least one filter zone interposed between the wicking membrane and the reservoir pad. The filter zone being operable to permit passage of any specific immunocomplex to the wicking membrane while impeding passage of larger components.

Immunoassay devices and materials

The polymorphism of bismuth sesquioxide

1
Nach einer Ubersicht uber heterotype Mischphasenbildung mit im Rutil- und Fluoritgitter kristallisierenden Wirten wird die Darstellung von Fluoritmischphasen der Dioxide von Uran, Thorium, Cer und Zirkonium mit Wismutoxid beschrieben.

2
Von den Mischphasen werden Farbe, Gitterkonstanten, pyknometrisch bestimmte Dichten und die fur zwei Fehlordnungsarten berechneten Rontgendichten angegeben.

3
Im System UO2BiO1,5 erstreckt sich eine. Fluoritphase von UO2 bis 100 Mol-% BiO1,5 (δ-Bi2O3) im ganzen Phasenbereich ist die Kationenpunktlage voll besetzt und nehmen die Anionenlucken mit steigendem BiO1,5-Gehalt laufend zu.

4
Im System ThO2BiO1,5 reicht die Fluoritphase von 0 bis etwa 60 Mol-% BiO1,5 bei gleicher Fehlordnung der Phase wie unter 3.

5
Im System CeO2BiO1,5 beobachtet man eine Fluoritphase von 0 bis etwa 40 Mol-% BiO1,5 bei gleicher Fehlordnungsart wie unter 3.

6
Im System ZrO2BiO1,5 tritt von etwa 30 bis 100 Mol-% BiO1,5 die zweidimensional geordnete Fluorituberstrukturphase des β-Bi2O3 auf. Aus dem Dichtevergleich folgen bei 100 Mol-% BiO1,5 ein ideal besetztes Kationenteilgitter und Lucken im Anionenteilgitter; bei 40 Mol-% BiO1,5 liegt ein ideal besetztes Anionenteilgitter mit Kationen auf Zwischengitterplatzen vor; zwischen beiden Zusammensetzungen der Mischphasen geht die eine Fehlordnungsart in die andere kontinuierlich uber.





The preparations, colours, lattice constants, experimental and X-ray densities of fluorite-type mixed phases between bismuth(III) oxide and the dioxides of U, Th, Ce, and Zr are described.



In the systems UO2BiO1.5, ThO2BiO1.5 and CeO2BiO1.5, fluorite phases occur from 0 to 100, 60 and 40 mole per cent BiO1.5, respectively, with all cation positions being occupied and anion vacancies increasing with higher BiO1.5 contents.



In the system ZrO2BiO1.5, ThO2BiO1.5 and CeO2BiO1.5, fluorite phases occur from 0 to 100, 60 and 40 mole per cent BiO1.5, respectively, with all cation positions being occupied and anion vacancies increasing with higher BiO1.5 contents.



In the system ZrO2BiO1.5 the two-dimensionally ordered fluorite superstructure of β-Bi2O3 occurs from 30 to 100 mole per cent BiO1.5. Whereas the pure β-Bi2O3 has an ideally occupied cation lattice and vacancies in the anion lattice, at 40 mole per cent BiO1.5 there is an ideally filled anion lattice with interstitial cations.

Fluoritmischphasen der Dioxide von Uran, Thorium, Cer und Zirkonium mit Wismutoxid

Die Darstellung der Verbindungen wird beschrieben. Die weisen Verbindungen werden in Zusammensetzung und Kristallstruktur durch chemische und rontgenographische Analyse sowie Dichten charakterisiert. Mit 1 Molekel/Zelle kristallisieren die Verbindungen im kubischen Sodalithgitter. Durch Gluhen des weisen Rhodanid-Sodaliths an Luft oder in N2 bei 1000°C erhalt man ein leuchtend blaugrunes oder ein gelbes Pigment.



Nitrite, Cyanide, and Thiocyanate Sodalite



The synthesis of the compound is described. The white compounds are characterized in composition and crystal structure by chemical and X-ray analysis and densities. The unimolecular cubic cell of the compounds has sodalite structure. By heating of the thiocyanate sodalite at 1000°C in air or in N2 there are produced a bright blue green or a yellow pigment.

Nitrit-, Cyanid- und Rhodanid-Sodalith

Colored and uncolored inorganic pigments have been obtained since prehistoric times from natural minerals, at first empirically, then by specially developed methods. Since the beginning of the 18th century they have also gradually come to be studied scientifically, and today such research makes use of the latest techniques of solid-state physics and chemistry. On the basis of our knowledge of technically and aesthetically important properties, it has been possible in the last seventy years to make synthetic pigments superior to the natural ones, to increase production drastically while maintaining the pigment properties unchanged or improving them, and to broaden the range by the addition of new synthetic pigments. Nowadays it is in principle possible to write down a specification for many fields of application, taking into account aesthetic, technical, economic, and ecological aspects, and to make the corresponding inorganic pigment in adequate amounts. In what follows I shall discuss the dependence of the scattering and absorption constants of pigments on the refractive index, the wavelength of the light and the particle size, the properties of pigmented systems that depend on the particle geometry, and also some of the optical characteristics determined by the arrangement of the atoms in the crystal lattice.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/anie.198107231

Inorganic Pigments: Bases for Colored, Uncolored, and Transparent Products

An Fe3 O4 iron oxide black pigment having incorporated therein up to about 50 mole percent of γ-Fe2 O3 plus Me Fe2 O4 (wherein Me is at least one of magnesium, manganese, cobalt, nickel, aluminum, chromium, titanium, copper, zinc and cadmium) having a specific surface according to BET of greater than about 12 m2 /g, up to about 10% by weight of a substantially insoluble inorganic compound as coating and a stability to oxidation with air under standardized conditions of greater than about 130° C. Advantageously the coating comprises at least one of zinc hydroxide, zinc phosphate, zinc phosphite, aluminum phosphate and silica, being precipitated onto the suspended pigment from a solution. The resulting pigments are of improved resistance to oxidation, rendering them especially useful for pigmenting inorganic and organic dispersions and for use on magnetogram supports.

Production of iron oxide pigments with improved resistance to oxidation

In the production of a precipitated red iron (III) oxide pigment of hematite structure wherein an aqueous iron (II) salt solution is mixed with an aqueous alkali solution in substantially equivalent quantities to produce an aqueous suspension of iron (II) hydroxide or carbonate, the suspension is oxidized by passing oxygen-containing gases through it with stirring under atmospheric pressure at a temperature of about 0° to 50°C, and the resulting iron (III) seed suspension is allowed to grow into precipitated red iron (III) oxide pigment by further oxidation with an oxygen-containing gas at a temperature of about 50° to 100°C in the presence of more iron (II) salt and alkali solution or in the presence of iron (II) salt and metallic iron at a pH-value kept in the acid range, the improvement which comprises producing the iron (III) seed suspension in the presence of a foreign modifying substance so that lattice-distorted, chemically reactive finely divided delta-FeOOH seeds are formed, whereby the resulting red iron (III) oxide pigment contains less than about 15 % by weight of α-FeOOH. The modifying substance may be a chloride of magnesium, calcium or aluminum, vanadium pentoxide, sodium phosphate, erythritol, mannitol, glyceric acid, K, Na-tartrate, Na-citrate, ribose, glucose, fructose, tannin, or NH 4 --, Ca--, Al--, Fe or Mg-lignin sulfonate.

Franz Hund

Papers

Fluoritmischphasen der Dioxide von Uran, Thorium, Cer und Zirkonium mit Wismutoxid

Nitrit-, Cyanid- und Rhodanid-Sodalith

Inorganic Pigments: Bases for Colored, Uncolored, and Transparent Products

Production of iron oxide pigments with improved resistance to oxidation

Production of precipitated red iron (III) oxide pigment relatively free of α-FEOOH