EURONS Town Meeting 2008
September 17 - 19, 2008 -
Information

Title:	Mr.
Family Name:	Pereira
First Name:	Lino
Gender:	male
E-Mail:	linomcpfc.up.pt
Affiliation for Badge:	ITN, Lisboa
Institute:
Address (Street):	Estrada Nacional 10
Postal Code, City:	2686-953 Sacavém
Country:	Portugal
Phone:	+351967564080
Fax:
Young researcher with contribution:	Yes
Arrival Date:	September 16
Departure Date:	September 20
Author(s):	L.M.C. Pereira1,2,4,5 U. Wahl3,4 J.G. Correia3,4,5 J.P. Araújo1,2
Institute(s):	1Faculdade de Ciências da Universidade do Porto, Portugal 2Instituto de Física de Materiais da Universidade do Porto, Portugal 3Centro de Física Nuclear da Universidade de Lisboa, Portugal 4Instituto Tecnológico e Nuclear, Portugal 5CERN-PH, Switzerland
Title:	Recent Emission Channeling Studies in Transition Metal doped ZnO
Abstract:	Magnetically doped semiconductors (dilute magnetic semiconductors - DMS) are seen as strong candidates to make use of the carriers spin in spintronic devices. Latest results of both experiment and theory are driving the research focus towards oxide semiconductors (mainly ZnO) doped with 3d transition metals (mainly Fe, Co, Mn and Ni). Any attempt to understand the room temperature ferromagnetism observed in these systems, something which still remains far from being accomplished, must start from a quantitative knowledge of the (magnetic) impurities lattice sites. In particular, such knowledge will give a final answer to the common criticism towards the reported room temperature ferromagnetism in DMSs, that is, the possibility of a non-intrinsic origin, establishing whether the observed properties are indeed related to a diluted alloy between the dopant and the host semiconductor or merely from ferromagnetic secondary phases. We present preliminary analysis of two recent emission channeling experiments on the lattice location of implanted Fe and Co in wurtzite ZnO. The angular distribution of beta particles emitted by 59Fe/61Co was monitored with a position-sensitive electron detector, following 60 keV room-temperature implantations of the precursor isotopes 59Mn/61Mn. In both cases the majority of implanted atoms are found on substitutional Zn sites. The root mean square displacements from the ideal substitutional and Zn sites are given and the stability of the dopants lattice location against thermal annealing is discussed.

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