Natur und Aufbau der Eisensalmiake Eie Beitrag zur Kenntnis der anomalen Mischkristalle

Abstract

Für das Zustandekommen anomaler Mischkristalle mit NH4Cl wird folgende Regel aufgestellt: Schwermetallchloride, die mit NH4Cl entweder keine Doppelsalze bilden können oder solche, die in sehr hohem Maße dazu befähigt sind bzw. solche, deren Doppelsalze schwer löslich sind, geben keine anomalen Mischkristalle mit NH4Cl. Schwermetallchloride, die nur dann Doppelsalze mit NH4Cl bilden, wenn die Lösung genügende Mengen dieser Chloride enthält, neigen in an Schwermetallchloriden armen Lösungen zur Bildung anomaler Mischkristalle.

Anomalous Isomorphism and Mixed Crystals in the Systems NH4Cl:(Cu,Mn)

“…However, between these relatively well studied limiting cases, there is a world of mixed crystals composed of nanometer to micrometer size blocks of different phases related to each other by crystallographic relationships. Pioneer work was done on mixtures of simple salts like ammonium chloride and transition metal chloride cocrystallizing from aqueous solutions. − Later, salts and molecular crystals were found to form mixed crystals with big dye molecules. , Independently, complex intergrowth of several phases were found among oxides, ferrites, high-temperature superconductors, , and various minerals including biopyriboles, carbonates, and sheet silicates. − Additionally, to direct crystallization, anomalous mixed crystals can form by means of solid state reactions. , Nowadays, increasing attention is paid to different crystal-complex organic molecules and crystal-polymer composites, , which are of high importance for biomineralization.…”

“…This article reports the first systematic study of mixed crystals forming in two similar and classic systems NH 4 Cl–MeCl 2 –H 2 O–CONH 3 (Me = Cu, Mn), where the Me 2+ bearing guest phases are incorporated into the host ammonium chloride crystal. Although these and similar systems were paid significant attention in the past, − ,− most of the studies were based only on measurements of total impurity concentration in a crystal and were carried out without application of X-ray diffraction methods and microscopic techniques like AFM and SEM. As a result, little is known about forms of impurity incorporation, sizes of impurity domains, mutual orientations between host and guest phases, growth mechanisms, and crystallization kinetics.…”