Deuteron NMR spectra of ND4ClO4 single crystal at low temperatures.
2H NMR spectra of ND4ClO4 single crystal were obtained at v0 = 44 MHz. Orientation and temperature (1.9-75 K) dependences were measured. Fitting the spectra gives the effective quadrupole coupling constants for all deuterons and the ground torsional level structure. The isotope reduction of the (A-T) and (A-E) tunnelling splittings, i.e., the ratios of the respective splittings for NH4+ and ND4+, were found to be different. The splittings at T = 24 K are about 60% of the helium temperature values. The spectrum undergoes intermediate narrowing by reorientations between 26 and 34 K and tunnelling related features in the spectra are eradicated. After reaching the extreme narrowing limit, a doublet with gradually decreasing separation was observed, what was attributed to averaging by torsional oscillations of increasing amplitude. At high temperatures (T > 75 K), the narrow spectrum reflects fast multiaxial reorientation of the ammonium ion.
An analysis of the NMR line shapes of the ammonium ion undergoing composite tunneling and reorientational motions at low temperatures
An analysis is made of the NMR line shapes of the rotationally tunneling ammonium (NH4+) ion which also undergoes rapid reorientataional jumps around its C3 or C2 symmetry axis. The proposed composite motion, believed to be brought about by the coupling of rotor states of the ion with lattice phonons, leads to line narrowing and offers an interpretation of experimental line shape and second moment data not explained previously. In particular, the proton resonance line shapes of (NH4)2SnCl6, NH4BF4, NH4ClO4, (NH4)2GeF6, (NH4)2PbCl6, and (NH4)2PtCl6 at liquid helium temperatures are discussed. The analysis suggests that proton magnetic resonance line shape measurements on single crystals may provide an assessment on the state of ordering of the tunneling and reorienting NH4+ ions.
Religion and school
The report presents and argues in favor of the thesis that the secular school offers no alternative in modern society. Simultaneously, the author displays the basic contours of spiritual physiognomy of such a modern school which in many ways differs from the, school we know in this country. The school the author pleads for does not decide among various contents that influence forming of the young, within which the line is established between theism - atheism, but, on the contrary, pleads for the principle of humanistic education. The predominant here is the notion of methodological skepticism which marks the principle by which the process of education should be realized as though there were no God, or - which is on the same level - as though there were God. Out of this basic principle any others upon which the concept of modern secular school the author pleads for is established can be drawn. It ought not to neglect the rich, scientifically confirmed knowledge on the phenomenon of religion and atheism, which should be, presented in all school subjects where the contents allow for it as well as the Religious Culture should be introduced as a compulsory subject. By introducing this subject as a collection of knowledge on the phenomenon of the, religious, we would avoid imposing a particular religious culture as an attitude, behavior, belief and evaluation.