Sodium magnetic properties

Hydrothermal Method. Iron [Fe(III)], barium, and the dopants are precipitated as their hydroxides and reacted with an excess of sodium hydroxide solution (up to 6 mol/L) at 250-350 °C in an autoclave. This is generally followed by an annealing treatment at 750-800°C to obtain products with the desired magnetic properties. Many variations of the process have been described [5.36]-[5.40], the earliest report being from 1969 [5.41], In later processes, hydrothermal synthesis is followed by coating with cubic ferrites, a process resembling the cobalt modification of iron oxides (see Section 5.1.2). The object is to increase the saturation magnetization of the material [5.42]-[5.44],... 

W. Plotnikoff found the mol. conductivity of ethereal soln. diminishes with dilution, and increases with rise of temp. W. Hittorf attempted to determine the transport number of the anion in aq. soln. of normal sodium phosphate, but the salt was so much hydrolyzed that most of the current was carried by the alkali. With aq. soln. of sodium hydrophosphate, the transport number of the HP0"4-anion was 0-516 and with sodium dihydrophosphate for the H2PO 4-anion, 0-383. J. F. Daniell and W. A. Miller also made some observations with this salt. W. Hittorf found with soln. of potassium dihydrophosphate, the transport number of the H2P0,4-amon was 0-277. O. Wosnessensky measured the potential difference at the boundary of phosphoric acid and a non-aqueous solvent. P. Pascal studied the magnetic properties. J. Murray tried if he could decompose a soln. of the acid by magnetized iron. 

There is reason to believe that an equilibrium of this type exists between the sodium ions and the electrion to form an ion pair as a result of coulombic interactions. If the conductance data for sodium are used to determine the equilibrium constant of sodium in liquid ammonia for computing the constant of the ion pair equilibrium, the experimental data do not conform to values required for such an equilibrium. This is because electrons in dilute solutions exhibit magnetic properties, from which we may conclude that, at very low concentrations, the electron has a spin of l/2 Bohr unit. It is, therefore, necessary to take into account the effect of the decreasing proportion of electrons that may be spin-coupled and interacting with the positive ions of the solvent. One of us (Evers) made the simplest possible assumption, following a model proposed by Becker, Lindquist, and Alder (BLA), namely that when two ion pairs, consisting of a sodium ion and an electron, come together the spins of the two electrons couple to form disodium spinide, and that this coulombic compound is not dissociated into ions at low concentrations. 

Used as an indicator of the purity of organic compounds, it is related to several electric and magnetic properties such as polarizability as well as to molar refractivity, critical temperature, surface tension, density, and boiling point. Usually, the refractive index is measured at the sodium D-line and indicated as n. Moreover, the refractive index function n) defined as... 

The electrical and/or magnetic properties of a number of mixed oxides of A1 and other metals including members of the spinel family (see Box 12.6) and sodium P-alumina (see Section 27.3) have extremely important industrial applications. In this section, we single out Ca3Al205 because of its role in cement manufacture, and because it contains a... 

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