Sep 12 – 17, 2010
CERN
Europe/Zurich timezone
The conference is now over. Thanks to all for their participation. <p> The talks from the various sessions are all online.

Hyperfine local probe study of alkaline-earth manganites BaMnO3 and SrMnO3

Not scheduled
500/1-001 - Main Auditorium (CERN)

500/1-001 - Main Auditorium

CERN

CH - 1211 Geneva 23 Switzerland
72
Show room on map
POSTER Magnetism and Magnetic materials - Bulk and thin layers

Speaker

J. N. Gonçalves (Departmento de Física and CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal)

Description

text + figure + references

Summary

We report perturbed angular correlations (PAC) and first-principles calculations with 111mCd/111Cd and
111In/111mCd probes, implanted at the ISOLDE-CERN laboratory, in the compounds/polymorphs
BaMnO3-6H and BaMnO3-15R and SrMnO3-4H. Magnetic and structural studies were also performed.
The experiments are complemented with calculations of the electric field gradient (EFG), with density
functional theory, by the LAPW method (Wien2k code [1]). Calculations consider different magnetic
states, and for the case of BaMnO3 the results from different polymorphs are analyzed. Comparison
with the experimental results requires considering supercells with diluted Cd impurities, to account for
the presence of the radioactive probe in the host material (ppm). The results of the calculations are
checked for convergence with increasing dilution of Cd probes, corresponding to increasing size of the
supercell. Based on the calculations, the assignment of the sites for the 111mCd and 111In probes at the
Ba (for BaMnO3-6H) and Sr (SrMnO3-4H) sites gives good agreement for most cases. The EFG shows
no visible changes with temperature in BaMnO3-6H and SrMnO3-4H, in the range 20-700 C, as shown
in the figure). The PAC spectra of BaMnO3 in the two polymorphs reveal different frequencies. The
results on BaMnO3 using 111In/111mCd, show an additional interaction frequency in comparison with Cd.

Are you a student, a delegate from developing countries or a participant with physical needs and would like to apply for a sponsored accomodation. Please answer with yes or no. yes
Please specify whether you would prefer an oral or poster contribution. poster

Primary author

J. N. Gonçalves (Departmento de Física and CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal)

Co-authors

A. M. L. Lopes (CFNUL, Av. Prof. Gama Pinto 2, P-1699 Lisboa, Portugal) H. Haas (Instituto Tecnológico e Nuclear, E.N. 10, 2686-953 Sacavém, CFNUL, Av. Prof. Gama Pinto 2, P-1699 Lisboa, Portugal) J. G. Correia (Instituto Tecnológico e Nuclear, E.N. 10, 2686-953 Sacavém, CFNUL, Av. Prof. Gama Pinto 2, P-1699 Lisboa, Portugal) V. S. Amaral (Departmento de Física and CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal)

Presentation materials

There are no materials yet.