Nitride fluorides

Subsequent treatment of (NH4)2MF6 in a carefully dried stream of NH3 affords stepwise release of NH4F. Three intermediate phases were isolated so far, but in none of the cases was the respective nitride fluoride formed (Table 2). 

Table 5. Non-commensurate oxide- and nitride-fluorides of Zr and the rare earths (Lattice vectors in A, angles in degrees.)... 

The growth of ZnS him is another often used classical example for illustrating the principles of the ALD process. ZnCl2 and H2S are used as precursors. First, ZnCl2 is chemisorbed on the substrate, then H2S is introduced to react with ZnCl2 to deposit a monolayer of ZnS on the substrate and HCl is released as a byproduct. A wide spectrum of precursor materials and chemical reactions has been studied for the deposition of thin films by ALD. Thin films of various materials including various oxides, nitrides, fluorides, elements, and II-VI, II-VI, and III-V compounds in epitaxial, polycrystalline, and amorphous form deposited by ALD are summarized in Table 20.1. ... 

In this book, we briefly examine the different types of reactions and methods employed in the synthesis of inorganic solid materials. Besides the traditional ceramic procedures, we discuss precursor methods, combustion method, topochemical reactions, intercalation reactions, ion-exchange reactions, alkali-flux method, sol-gel method, mechanochemical synthesis, microwave synthesis, electrochemical methods, pyrosol process, arc and skull methods and high-pressure methods. Hydrothermal and solvothermal syntheses are discussed separately and also in sections dealing with specific materials. Superconducting cuprates and intergrowth structures are discussed in separate sections. Synthesis of nanomaterials is dealt with in some detail. Synthetic methods for metal borides, carbides, nitrides, fluorides, sili-cides, phosphides and chalcogenides are also outlined. 

Nitride, fluoride and sulfide bond strength and bond length variations... 

Nitride halides and nitride sulfides constitute another family of rare-earth-containing compounds. The variety concerns the richness of the different formulations as well as the nature itself of the compounds. Except in the case of nitride fluorides which have a clear salt behavior, nitrogen atoms generally do not play the same role as Cl" or S anions in some cases it is even difficult to know whether the borderline between a valence compound and a cluster compound has not been crossed. 

Whereas CeNF was not obtained as a cerium nitride fluoride, CeNCl was shown by Ehrlich et al. (1994) to crystallize with the layered tetragonal (P4/nmm) BiOCl-type structure, like ThNCl (Juza and Sievers 1968). 

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