| AVS 63rd International Symposium & Exhibition | |
| Actinides and Rare Earths Focus Topic | Wednesday Sessions |
| Session AC+MI-WeM |
| Session: | Magnetism, Complexity, and Superconductivity in the Actinides and Rare Earths (8:00-11:00 am)/Actinide and Rare Earth Theory (11:00 am-12:20 pm) |
| Presenter: | Itzhak Halevy, Physics Department |
| Authors: | I. Halevy, Physics Department B. Glam, NRC Soreq, Israel S. Maskova, Charles University, Prague, Czech Republic D. Moreno, NRC Soreq, Israel S. Eliezer, NRC Soreq Shalom Eliezer2, Israel |
| Correspondent: | Click to Email |
High pressure investigation of the crystallographic structure and bulk modulus of aluminum containing helium bubbles is presented. The targets were obtained by melting pure aluminum with 0.15% wt.10B powder. The solid targets were neutron irradiated in the Soreq nuclear reactor to get homogeneous helium atoms inside the aluminum boron 10 matrix according to the reaction 10B+n→7Li+4He. The irradiated aluminum was heat treated for accumulation of helium atoms into nanometric bubbles by diffusion . The helium bubbles formation in Al–10B metal was observed by TEM.
The crystallographic structure and the bulk modulus of aluminum loaded up to pressure of 39 GPa in a diamond anvil cell (DAC) were studied in different samples: (1) Al-10B, (2) Irradiated Al-10B with helium bubbles (3) The irradiated Al-10B foil with helium bubbles that was used for TEM observation.
The data was analyzed by the X’Pert Plus (Philips) Rietveld analysis software packages. The high-pressure energy dispersive X-ray diffraction studies were taken at the X17-C beam-line of the National Synchrotron Light Source (NSLS) at BNL [ 1 ]. The energy dispersive data was collected with a high purity germanium detector at a fixed Bragg angle (2Θ∼=12◦). The high-pressure X-ray powder diffraction measurements were taken at discrete pressure steps in the range of 0– 35 GPa. The data wascollected by the EDS technique, using the white beam of the superconducting wiggler magnet at the X17-C beam-line. Typical data collection time was about 10 min. Inthe lower range of the high-pressure range, angle dispersive measurements were carried out in transmission configuration using the image plate technique. The data was analyzed using acommercial Rietveld analysis software packages [2].
The Pressure as function of V/V0 was fitted by Vinet equation to yield the B0 and B0' of the EOS. B0 and B0' are the bulk modulus and its pressure derivative at the equilibrium volume V0 at zero pressure. For our pure Al B0=68.6GPa while B0' was kept at 3.6 .
Our early work with SEM and TEM showed He bubals as the sample was radiated.
Quantum Design SQUID equipment was used for magnetic studies of bulk Al-15wt.% B and pure Al. Magnetic measurements were performed in the temperature range 2-300 K and fields up to 7 T.
Results of the susceptibility measurements, c(T), are summarized . The susceptibility is field independent in the whole temperature range studied. All “samples” have similar weak temperature dependence, with c-values somewhat below 1*10-10m3/mol.
References
[1] Hu, J.: High pressure X-ray beam line X17C. www.bnl.gov/x17c. Updated 07/01/2007
[2] Rietveld, H.M.: J. Appl. Crystallogr. 2, 65 (1969)