Saturated ferromagnetism and magnetization deficit in optimally annealed (formula presented) epilayers

Physical Review B - Condensed Matter and Materials Physics

Volumn 66, Issue 1, 2002, Pages 1-4

  Potashnik, S J ^a   Ku, K C ^a   Mahendiran, R ^a   Chun, S H ^a   Wang, R F ^a   Samarth, N ^a   Schiffer, P ^a  

^a PENNSYLVANIA STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 16344370324     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.66.012408     Document Type: Article

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30. The lattice constant is determined through a complex interplay between Mn concentration and the intricate defect structure inherent to these materials. One might suspect that, based on the x-ray data, the large x samples have essentially the same Mn concentration due to diffusion of excess Mn ions to the surface during annealing. We can exclude such a scenario since the EMPA measurements (performed at 3 kV) probe the average Mn concentration in roughly the top half of the (formula presented) epilayers. Since both as-grown and annealed samples give the same EMPA results within experimental uncertainty, it is unlikely that any significant diffusion of Mn ions toward the surface occurs during the annealing process. In addition, such an inhomogeneous distribution of Mn would result in the formation of ferromagnetic MnAs phases since the average Mn concentration is already close to the solubility limit of homogeneous (formula presented) Neither x-ray diffraction nor magnetization measurements indicate any detectable traces of MnAs.
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