- Email: [email protected]
The LIII X-ray emission edge in lanthanum hydrides
ii
J.
ABSTRACTS OF PAPERS TO APPEAR IN
point in order to sudy the properties of the super-
PHYS. CHEM. SOLIDS
Vol. 9, No. 2
TbCo
cooled state. From the results of the measurements of Knight shift and electronic magnetic susceptibility, a difference in the temperature dependence was detected between the supercooled liquid and the normal liquid of gallium and gallium— indium eutectic alloy. On the other hand, the measurements of electrical resistivity and density did not indicate any discontinuous change. The temperature dependences of effective mass ratio
0 3Al crystallizes with the cubic MgCu2 type structure. The material orders close to ferromagnetically in a field of 30 koe but exhibits a Neel point of 35 K in a field of 500 oe. At 1.6K the magnetization increases in two discontinuous steps to an extrapolated saturation moment of 6.58 ~. A neutron diffraction experiment at 4.2ferromagnetically K shows a magnetic of 1~Bordered onlymoment at the Tb 6.98 sites. The situation seems to be similar to
and average probability density at the nucleus
ErCo
for the s-electrons on the Fermi surface were
2—ErAl2 alloys, where disordered antiferromagnetic components stabilize as a function of
calculated by using the observed results of Knight shift, magnetic susceptibility and density for liquid gallium. From these results a structural change may be expected between the supercooled and the normal liquid gallium. Received 28 July 1970
the free electron concentration. Received 2 September 1970 Revised 27 October 1970
6.
Revised 12 October 1970
4.
New evidence supporting the hydridic model of bonding in rare earth hydrides is reported. A weak peak was detected at the L111 X-ray emission edge of lanthanum metal and assigned to transitions involving conduction band electrons, L111O1vvand L~ i~. The regular decrease in intensity at the L1~1emission edge with increasing hydrogen content and the close similarity of the emission edges of LaH2 88’ La2O~and LaF3 support the view that hydride ions form at the expense of the population of the lanthanum conduction band. Received 27 May 1970 Revised 12 October 1970 5.
R. Hales, Berkeley Nuclear Laboratories Berkeley, Gloucestershire, U.K.
THE L111 X-RAY EMISSION EDGE IN LANTHANUM HYDRIDES Atul C. Sarma and William G. Bos, Department of Chemistry, University of Louisville, Louisville, Kentucky 40208
THE ORIGIN OF THE NEAR-SURFACE EFFECT OF DIFFUSION IN OXIDISING METALS
Solution to the diffustion equation are derived which describe the effect of a surface oxide barrier and of a vacancy flux on the distribution of a tracer element diffusing into a semi-infinite bar. The solutions are compared with the available experimental data on the diffusion of Cu into Pb and Ag into Mg. Received 8 September 1970 Revised 15 October 1970
7.
COMPARISON OF CALCULATED AND MEASURED LOWER CRITICAL FIELD FOR SOME Nb—Ti ALLOYS M.S. Lubell and R.H. Kernohan, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
MAGNETIC CHARACTERISTICS OF TbCo03A117
An expression is obtained from the Maki theory for H~ (0) in terms of three measurable material constants T~, p,~, and H~2(0). The calculations are compared to the measured H~1vs.
Hans Oesterreicher, Oregon Graduate Center, 9340 S.W. Barnes Road, Portland, Oregon 97225
T extrapolated to T = 0°Kfor three vacuum annealed Nb—Ti alloys. Values of H~1(0) are also determined from the computation of Harden and Arp.
J.
ABSTRACTS OF PAPERS TO APPEAR IN
point in order to sudy the properties of the super-
PHYS. CHEM. SOLIDS
Vol. 9, No. 2
TbCo
cooled state. From the results of the measurements of Knight shift and electronic magnetic susceptibility, a difference in the temperature dependence was detected between the supercooled liquid and the normal liquid of gallium and gallium— indium eutectic alloy. On the other hand, the measurements of electrical resistivity and density did not indicate any discontinuous change. The temperature dependences of effective mass ratio
0 3Al crystallizes with the cubic MgCu2 type structure. The material orders close to ferromagnetically in a field of 30 koe but exhibits a Neel point of 35 K in a field of 500 oe. At 1.6K the magnetization increases in two discontinuous steps to an extrapolated saturation moment of 6.58 ~. A neutron diffraction experiment at 4.2ferromagnetically K shows a magnetic of 1~Bordered onlymoment at the Tb 6.98 sites. The situation seems to be similar to
and average probability density at the nucleus
ErCo
for the s-electrons on the Fermi surface were
2—ErAl2 alloys, where disordered antiferromagnetic components stabilize as a function of
calculated by using the observed results of Knight shift, magnetic susceptibility and density for liquid gallium. From these results a structural change may be expected between the supercooled and the normal liquid gallium. Received 28 July 1970
the free electron concentration. Received 2 September 1970 Revised 27 October 1970
6.
Revised 12 October 1970
4.
New evidence supporting the hydridic model of bonding in rare earth hydrides is reported. A weak peak was detected at the L111 X-ray emission edge of lanthanum metal and assigned to transitions involving conduction band electrons, L111O1vvand L~ i~. The regular decrease in intensity at the L1~1emission edge with increasing hydrogen content and the close similarity of the emission edges of LaH2 88’ La2O~and LaF3 support the view that hydride ions form at the expense of the population of the lanthanum conduction band. Received 27 May 1970 Revised 12 October 1970 5.
R. Hales, Berkeley Nuclear Laboratories Berkeley, Gloucestershire, U.K.
THE L111 X-RAY EMISSION EDGE IN LANTHANUM HYDRIDES Atul C. Sarma and William G. Bos, Department of Chemistry, University of Louisville, Louisville, Kentucky 40208
THE ORIGIN OF THE NEAR-SURFACE EFFECT OF DIFFUSION IN OXIDISING METALS
Solution to the diffustion equation are derived which describe the effect of a surface oxide barrier and of a vacancy flux on the distribution of a tracer element diffusing into a semi-infinite bar. The solutions are compared with the available experimental data on the diffusion of Cu into Pb and Ag into Mg. Received 8 September 1970 Revised 15 October 1970
7.
COMPARISON OF CALCULATED AND MEASURED LOWER CRITICAL FIELD FOR SOME Nb—Ti ALLOYS M.S. Lubell and R.H. Kernohan, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
MAGNETIC CHARACTERISTICS OF TbCo03A117
An expression is obtained from the Maki theory for H~ (0) in terms of three measurable material constants T~, p,~, and H~2(0). The calculations are compared to the measured H~1vs.
Hans Oesterreicher, Oregon Graduate Center, 9340 S.W. Barnes Road, Portland, Oregon 97225
T extrapolated to T = 0°Kfor three vacuum annealed Nb—Ti alloys. Values of H~1(0) are also determined from the computation of Harden and Arp.