Pnictides magnetic properties

Relations between the structure and properties have been investigated in a variety of solids such as metal oxides, chalcogenides, pnictides and halides. In addition to studying model systems for testing theoretical predictions, solid state chemists have been preparing new classes of solids as well as novel members of known types of solids. In this section, we have chosen three classes of solids, viz. metal oxides, metal sulphides and metal fluorides, to discuss structure-property relations we shall concentrate especially on their electrical and magnetic properties. 

This prediction is a reasonable one for most cerium pnictides, namely CeP, CeAs, CeSb, and CeBi which, in fact, exhibit localized spin moments with an antiferromagnetic ordering of the 4/ electron remaining on each Ce [268]. CeN, however, is a metallic conductor with the corresponding magnetic properties and it only shows Pauli paramagnetism of the metallic electron gas, such that no local spin moment, characteristic for an unpaired electron, can be detected. This behavior leads to the possibility of an electronic formulation according to with one electron left in the conduction band, but... 

The Landolt-Bomstein Volume III/27 deals with the magnetic properties of non-metallic inorganic compounds based on transition elements, such as there are pnictides, chalcogenides, oxides, halides, borates, and finally phosphates and silicates, the latter presented in this subvolume I. A preliminary survey of the contents of all subvolumes that have already appeared or have been planned to appear is printed at the end of this volume. 

Westrum, E.F., Jr., 1968, Thermodynamic and Magnetic Properties of the Rare Earth Chal-cogenides, Pnictides, Halides and Binary Semimetallic Compounds, in Eyring, L., ed.. Progress in Science and Technology of the Rare Earths, Vol. 3 (Pergamon Press, New... 

Summary of the magnetic properties of the NaCl-fype pnictides... 

The Ce pnictides have been extensively studied for their magnetic properties and for the systematic variations in the two f peaks observed in photoemission. Because one... 

TbN, TbP, TbAs, TbSb, TbBi. In the terbium pnictides Tb is trivalent and the ground state in the cubic crystal field is a singlet (Trammell 1963, Lea et al. 1962). Pioneering results on the magnetic properties were published by Wilkinson et al. (1962) and Child et al. (1963), based on neutron diffraction experiments. 

The influence of the CEF on the magnetic properties of NpP was studied theoretically for all pnictides by Lam and Fradin (1974). The state of the art of powder measurements was summarized by Lander (1978). High-field powder measurements on NpAs were reported by Blaise et al. (1983). Measurements on powder of highly anisotropic compounds do not make sense, although the authors claim that they were able to bring the samples into a ferromagnetic state - a conclusion which turned out to be wrong. The observed reduction of the ordered moment was theoretically explained by Lam and Ellis (1985), based on a hybridization mechanism - a theory which still holds today. Mossbauer spectroscopy on NpSb by Sanchez et al. (1988) could be performed with no restrictions on the powdered samples. 

Pnictides. Plutonium nitride, PuN, has been studied as a possible fast-reactor fuel. It can be prepared by reaction of PuH with NH at 600—650°C or N2 above 230°C. The pnictides ate also interesting for their soHd-state magnetic and electrical properties. For the latter reason they also have been prepared as single crystals (165). 

Consider that atoms have a size range of about 1-2 A. Most inorganic solids, with the exception of halides, sulfides (and other pnictides), are based upon the oxygen atom, i.e.- oxide = O", whose atomic radius does not change even when sulfates, phosphates and silicates are formed. Oxide has an atomic diameter of 1.5 A or 0.15 nm. = 0.00015 (om. Nanoparticles are clumps of 1000 to 10,000 atoms. The latter would be a particle of 0.15 (om. in diameter. They can be metal oxides, semiconductors, or metals with novel properties useful for electronic, optical, magnetic and/or catalytic uses. 

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