A study of the Raman spectra of the alkoxyazoxybenzenes has revealed new bands which change markedly in all phases. Evidence is presented that indicates the existence of different alkoxy tail conformations between all observed phases. A tentative assignment of a band associated with an accordion mode is made.

Nuclear magnetic relaxation times have been measured for fractional monolayer coverages of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ adsorbed on Vycor glass. Above $\frac{1}{3}$ monolayer the spin-lattice relaxation time decreases sharply, and the spin-spin relaxation time increases, indicating a considerable change in the configuration and mobility of the atoms. Above ½ monolayer the atoms probably condense into a two-dimensional solid, with exchange tunneling of characteristic frequency considerably larger than that in bulk solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$.

We have studied one-phonon neutron scattering in liquid helium at a pressure of 24 atm in the range of wave-vector transfers $0.2 {\mathrm{\AA }}^{-1}<~\left|\overrightarrow{\mathrm{Q}}\right|<~0.7 {\mathrm{\AA }}^{-1}$ at $T=1.2\mathrm{}$ K. The results give a value (6.2 ± 0.6) × ${10}^{37}$ ${\mathrm{g}}^{-2\mathrm{}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\sec }^2$ for the parameter $\gamma$ which characterizes the phonon dispersion. The one-phonon peaks exhibit tails indicating shortened phonon life-times at elevated pressures.

Measurements of the 16-Hz susceptibility of a powdered ${\mathrm{Na}}_3$[${\mathrm{C}\mathrm{e}\left({\mathrm{C}}_7{\mathrm{H}}_3\mathrm{N}{\mathrm{O}}_4\right)}_3$] · 15${\mathrm{H}}_2$O (CDP) sample, in the shape of a right-circular cylinder with diameter equal to height, have been made as a function of the Johnson noise temperature $T_{\mathrm{J}}$ of a resistor in the range 2 to 20 mK. Pure liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ was used for thermal contact between the CDP and the noise thermometer in a demagnetization cell. The results are compared with similar data for cerium magnesium nitrate (CMN). CDP appears, like CMN, to have an anomalously low thermal resistance to pure liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$.

Measurements are reported (with $\approx 0.1$-eV resolution) of the $L_3{M}_{2, 3}$ $M_{4, 5}$ Auger-electron energy distributions from evaporated Ni and Cu using electron-beam excitation. The data reveal new structure (over an $\simeq$ 20-eV range) that could be correlated in part with the final states (for atomic Cu) and in part with overall features of the $3d$-band density of states determined by soft-x-ray emission spectroscopy and x-ray photoelectron spectroscopy.

Measurements of the electric field dependence of the conductivity have been made on the transition-metal oxide ${\mathrm{Ni}}_{0.6}$${\mathrm{Mn}}_{2.4}$${\mathrm{O}}_4$. It is found that the conductivity is a linear function of field to fields of 3 × ${10}^5$ V/cm after corrections for thermal response are made. The observed effect cannot be explained in terms of current theory of field-dependent hopping transport.

The steady magnetostriction of zinc has been measured between 1.3 K and room temperature in magnetic fields up to 22 kOe. From these length-change measurements, the uniaxial stress dependence $\frac{\partial \ln \chi }{\partial \sigma }$ of the steady susceptibility has been deduced for a uniaxial tension $\sigma$ parallel to the hexagonal axis. The stress dependence $\frac{\partial \ln {\chi }_{\parallel }}{\partial \sigma }$ shows an anomalous behavior similar to that of ${\chi }_{\parallel }$ as a function of temperature and is unusually large. The maximum value occurs at approximately 70 K where $\frac{\partial \ln {\chi }_{\parallel }}{\partial \sigma }=3.9\mathrm{}\times {10}^{-4}$ ${\mathrm{bar}}^{-1\mathrm{}}$.

We report the direct observation of transitions from the Cu $d$ levels in the valence band of CuIn${\mathrm{Se}}_2$. The fivefold degeneracy is completely lifted by spin-orbit interaction and the tetragonal crystal field in this chalcopyrite compound. From the observed polarization dependences, the symmetry of each of the five levels is determined. We show that a recent energy-band calculation ignoring $d$ levels is unable to account for the structure of the uppermost valence bands in I-III-${\mathrm{VI}}_2$ compounds.

The $2s$ and $3s$ electron spin densities at the nuclear site of ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ in iron metal were measured by a new technique combining the Mössbauer effect with electron spectroscopy. Ratios $\frac{{\left|{\psi }_{\mathrm{ns}}\uparrow \mathrm{}\right(0\left)\right|}^2}{{\left|{\psi }_{\mathrm{ns}}\downarrow \mathrm{}\right(0\left)\right|}^2}=0.9937\mathrm{}\pm 0.0015$ and 1.012 ± 0.006 were measured for $2s$ and $3s$ shells, respectively. These results are in qualitative agreement with theoretical calculations of the core contributions to the magnetic hyperfine interaction.

A new model is presented for the insulator-metal transition in Eu-rich EuO: At low temperatures the electrons are only very weakly bound to oxygen vacancies and conduction is metallic; near and above $T_c$ the electrons localize and form bound magnetic polarons by ordering the ${\mathrm{Eu}}^{2+}$ spins neighboring the vacancy, thereby gaining exchange energy. Magnetic-susceptibility data are presented which support this model.

The magnetic form factor of TmSb in an applied magnetic field of 12.5 kOe at 5 °K has been measured with polarized neutrons. The experimental points with $H\parallel 〈100〉$ fall on a smooth curve, whereas considerable anisotropy is observed with $H\parallel 〈110〉$. These effects arise from the interaction between the rare-earth ion and the crystal field. The agreement between the theoretical form factor, calculated by the tensor-operator method, and the experiment is excellent.

In this paper we describe the first measurements of the detailed angular dependence of antiresonance transmission of microwave radiation through thick ferromagnetic specimens. Although the total transmission amplitude at 23.7 GHz consisted of a single narrow peak in the exact perpendicular configuration, a rotation of the field through as little as ½° gave a transmission signal having a double peak. These observations are inconsistent with the simple theory of antiresonance transmission which neglects the exchange interaction between spins.

We compare the differential cross section at a proton energy of 39.8 MeV for the transition ${\mathrm{Ne}}^{22}\mathrm{}(p,t)\mathrm{}{\mathrm{Ne}}^{20}$ ($2^{-}$, 4.97 MeV), which is forbidden by the usual selection rules for a single-step process, with a coupled-channel Born-approximation calculation using rotational wave functions of the adiabatic form. The calculated results are in good agreement with the experimental data.

The $\mathrm{D}(p,2p)n$ cross section has been measured at $E_p=39.5\mathrm{}$ MeV using a unique multi-detector scattering chamber. The integrated cross section $\frac{d^4\sigma }{d{\Omega }_{4}d{E}_{3}d{E}_4}$ shows a prominent minimum due to destructive interference between the single-scattering term of the rescattering series and the higher order terms of the series. This destructive interference accounts for the failure of the simple impulse approximation to predict correctly the magnitude and shape of the quasifree scattering peak.

A study of simulated fission cross sections indicates that the number of missed levels for fissile nuclei can be considerably larger than has generally been believed. For a nucleus such as ${\mathrm{U}}^{235}$ with a number of open fission channels and a small level spacing, approximately half the levels are unobserved at 39 eV neutron energy for a target at room temperature.

When implanted in transition metals, the decay rate of ${}_{}{}^{235m}{}_{}{}^{}\mathrm{U}$ is influenced by the free-electron concentration of the host metal. The results can be qualitatively described by means of the "rigid-band" and "screened-potential" models.

The cross section of the reaction ${}_{}{}^4{}_{}{}^{}\mathrm{He}+\gamma \to p+{\pi }^{-}+\left(\mathrm{ppn}\right)\mathrm{}$ has been measured in the region of the first resonance for various values of the recoil momentum. An anomaly is observed for high values of this momentum and a tentative explanation is suggested.

Doppler-broadened $\gamma$-ray transitions have been observed for the first time in the reaction ${\mu }^{-}+(Z,A)\mathrm{}\to \mathrm{}(Z-1,A)+{\nu }_{\mu }$, which are suitable for analysis in terms of angular correlations between the neutrino and a de-excitation nuclear $\gamma$-ray. The observed transitions are interpreted in terms of $\gamma -\nu$ correlation coefficients which are functions of the weak-interaction coupling constants.

A proof of the Adler-Bardeen theorem is given with the aid of the Callan-Symanzik equation.

The cross section for photoionization is expressed as an integral over the dipole response function in a form that yields a unified procedure for calculating the background and the resonance contributions. Application is made to absorption by triplet metastable helium.