Exploring the Chemistry of Metallic Solids , including Superconductors


PDF file , 6154 KB (6.00 MB) , readable on any computer with the Adobe Acrobat Reader . Most computers already have this application installed . If required , the Acrobat Reader can be downloaded free from the Adobe website .

The book has 417 pages : text (372 pp.) , references (28 pp.) , a Table of Contents (5 pp.) , a Table of Illustrations (7 pp.) , and several miscellaneous pages .

The academic level of the book is about that of mid-level undergraduate college chemistry . It is mostly descriptive inorganic chemistry , with only a brief section of simple mathematical treatment . The text is profusely illustrated with GIF sketches , JPEG crystal models , and numerous Tables .

M3D model of YBCO (YBa2Cu3O7) , the first liquid nitrogen range superconductor (Tc = 93 K) . Yttrium : yellow sphere ; barium : violet ; copper : red ; oxygen : green .


A Brief Synopsis of the Ebook

Introduction : the interdisciplinary approach and contribution of chemistry and chemists to superconductor research . Superconductors as metallic solids .

Chemical bonding , metallic solids (structural : molecular , polymeric , lattice ; orbital topography of the metallic bond ; Krebs's theorem) .

Chemical classification of metallic solids (Robin-Day classes of mixed-valent compounds) . Proposed new classification of metallic solids (eight classes) . I've recently posted a new web page to the Chemexplore website , “A New Classification of Metallic Solids”. Electronic structure of metallic solids (valence bond for the covalent framework , molecular orbital for the metallic bond) ; hybrid MOs , crystal orbitals .

A survey of a wide range of interesting metallic solids : KCP (Peierls distortion) , Alchemist's Gold , silver subfluoride , poly(sulfur nitride) , TTF-TCNQ , NbO , CrO2 , ReO3 , tungsten bronzes , tin metal , SnP , Purple Plague , the Zintl concept and Zintl structures , Verwey's controlled valence concept and mixed-valency .

Niobium monoxide , NbO . Red spheres , niobium ; green spheres , oxygen .

The modern superconductors are surveyed and analysed : Bednorz and Müller's La-Sr/Ba-Cu-O systems ; YBCO ; Nd-Cu-O compounds ; Sr-Cu-O compounds ; thallium , bismuth , and mercury cuprates ; the Ba-K-Bi-O system ; and others .

Novel resonance-activated metallic systems are proposed .

Novel systems with zerovalent atoms inserted into unreactive host lattices are proposed .

It might be possible to insert copper atoms (red spheres) into the lattice of zinc oxide (zinc cations , blue , oxide anions green) to form layers of linear chains of copper(0) oxide in the hypothetical compound CuZnO . This is predicted to be a metallic material .

A new type of photovoltaic diode (solar cell) , based on structures of layered metallic compounds (instead of the conventional semiconductors) , is proposed . This concept is more fully explored in the web pages , “A New Solar Cell”, and “New Solar Cells from Mixed-Valent Metallic Compounds”.

Novel metallic solids based on elements from across the Periodic Table are proposed , utilizing the chemistry of mixed-valent compounds : from the alkali metals (the ammonia electrides , F centers) ; alkaline earth electrides ; transition metal elements (iron , cobalt , nickel , copper , and zinc) ; and post-transition elements (aluminum and tin) .

Fe3OSe (antiperovskite)

The above hypothetical iron-based compound might actually be a high temperature superconductor ! The black spheres represent iron ; the green ones are oxides ; and the yellow sphere in the center is a selenide anion . Fe3OSe and related M3OX antiperovskites (M = Fe , Co , Ni , and Zn ; X = sulfide , selenide , telluride , and maybe disulfide) are discussed in the web page , “Prediction of Superconductivity in Transition Metal Chalcogenide Oxides”, which can be downloaded here .

Simple crystal systems are studied : rocksalt , fluorite , rutile , spinel (normal and inverse) , ReO3 , antiReO3 , perovskite , semiperovskite , antiperovskite , delafossite , anticorundum , and shiskebab .

The informal classes of bronze , black , and gray metals are described (for example , high temperature superconductors would be considered as black metals) .

A simple picture of the magnetic polar coupling of antiparallel electron pairs is proposed to explain the differences between the "classical" BCS Cooper pairs and those associated with high temperature superconductors such as the cuprates . This magnetic coupling process is also outlined in the web pages “Antiferromagnetic Induction in High Temperature Superconductors”, and “A Survey of Superconductors”.

A critique of previous recommendations for raising the transition temperature of superconductors is offered , with my own recommendations added .

You are welcome to download this FREE ebook by clicking the download link below .


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