In contrast to the bulk system where the conventional phase diagram indicates no miscibility § 4 (onch
between Co and Cu at room temperature, the nanoscale PLD multilayers are partly mixed (12). The
inclination to mixing depends on the preparation technique that was used. In contrast to sputtered The anal
layers pulse laser deposited multilayers can be completely ballistically mixed. ne
electron Mm
3.3. Chemical Bonding of Oxygen in Nanoscale Fe-Al Multilayers solved. Sp
From the course of the electron energy loss near edge structure (ELNES) conclusions concerning Fo
the chemical bonding are possible. A careful inspection of ELNES in nanoscale Fe-Al multilayers. =:
(Figure 7) shows significant differences in the near edge fine structure of the K edges for oxygenin i
Fe or in Al respectively (13).
SiO
2 3, Refers
Fe i Ce
Lh . (2) Wetz
A Al (3) Hren,
£ - Plenu
An Fe 5 CE
a sticker (5) Ame
EY 20 nm Ca
: 7 WN (7) Bat
U (8) Mah
O-K Ce
x) (10) Park
| FT - <q -
Al-L / : Fe L (11) Jeno
(12) Thon
A | (13) Thor
oY
eda dL = i | i
100 200 500 400 500 600 "7305 500 600 700 800 900
Figure 7: Microstructure and EEL spectra of a nanoscale Fe-Al multilayer
left: fine structure of the O-K edge for ALO;
right: fine structure of the O-K edge for Fe oxide
A characteristic detail in the oxygen ELNES course in Fe is the distinct prepeak. This prepeak is
typical for the oxides of transition metals of the 4™ period where electron transition into vacant
O2p-Me3d mixed states takes place. The second oxygen spectrum belongs to ALO; as in
agreement with the fingerprint spectra. Therefore, from energy loss near edge structures it can be
distinguished between different nanoscale oxide phases.
16