3.2 Non-destructive Analysis Methods with Irradiation
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The release of energy after the deep-level ionization is also possible by the emission of another electron when the deep-level vacancy is filled. The electrons emitted
in this process are called Auger electrons and the name of the associated measurement is the Auger electron spectroscopy (AES). Unlike that of photoelectrons, the
energy of the Auger electrons does not depend on the energy of the original ionization
source, which is a distinctive feature of these electrons in the spectrum. For other
features like resolution and energy dependence on the oxidation state, AES electron
spectrometry exhibits a large analogy to XPS.
The nomenclature of the emitted radiation differs a bit, depending on the particle
emitted. The emitted primary electrons are named after the sign of the shell they come
from (K, L, …). If another electron fills up this vacancy and the leftover energy is
emitted by electromagnetic radiation, the first letter indicates the level that was filled
up, and the forthcoming Greek letter refers to the relative position of the shell from
which the electron jumps. For instance, K α (or K β ) means that the vacancy on the K
shell is filled up by another electron coming from the neighbouring (or the second
following) electron shell. The denotation of the Auger electrons emitted is composed
of three Latin letters: the shell at which the primary ionization took place, the shell
from which the vacancy is filled up and that from the Auger electron is emitted (e.g.,
KLL).
3.3 Thermal Analysis
In thermal analysis, a predefined temperature program is applied and the behaviour of
the sample is detected by using various methods. The properties detected as a result
of the annealing can be the structure of the sample, its weight (thermogravimetry,
TG), the heat flow during the annealing process (differential thermal analysis, DTA)
or the gaseous products emitted during the annealing. Each method can be performed
either in an inert atmosphere or in oxidizing media (air or pure oxygen). Thermal
measurements are typically performed in a controlled gas stream.
In the simplest case, the sample having a metastable structure undergoes some
structural relaxation and phase transformation upon annealing. The structure of the
sample can be detected with conventional diffractometric analysis at room temperature after particular periods (maximum temperatures and/or annealing times) after
which the samples are cooled again. In highly specific devices designed for in situ
structural observation, the diffraction pattern can be recorded at high temperature,
too.
While the diffractometric analysis of a sample series can give information on
the processes taking place, the threshold temperature of the structural transformation can seldom be established due to the limited number of samples treated. Since
the structural transformations are accompanied by some heat effect, its detection
during the annealing process offers a convenient tool to detect a collateral effect
of the structural transformation as a quazi-continuous function (i.e., measured with
frequently collected data point during the annealing process, not only by detecting
67
The release of energy after the deep-level ionization is also possible by the emission of another electron when the deep-level vacancy is filled. The electrons emitted
in this process are called Auger electrons and the name of the associated measurement is the Auger electron spectroscopy (AES). Unlike that of photoelectrons, the
energy of the Auger electrons does not depend on the energy of the original ionization
source, which is a distinctive feature of these electrons in the spectrum. For other
features like resolution and energy dependence on the oxidation state, AES electron
spectrometry exhibits a large analogy to XPS.
The nomenclature of the emitted radiation differs a bit, depending on the particle
emitted. The emitted primary electrons are named after the sign of the shell they come
from (K, L, …). If another electron fills up this vacancy and the leftover energy is
emitted by electromagnetic radiation, the first letter indicates the level that was filled
up, and the forthcoming Greek letter refers to the relative position of the shell from
which the electron jumps. For instance, K α (or K β ) means that the vacancy on the K
shell is filled up by another electron coming from the neighbouring (or the second
following) electron shell. The denotation of the Auger electrons emitted is composed
of three Latin letters: the shell at which the primary ionization took place, the shell
from which the vacancy is filled up and that from the Auger electron is emitted (e.g.,
KLL).
3.3 Thermal Analysis
In thermal analysis, a predefined temperature program is applied and the behaviour of
the sample is detected by using various methods. The properties detected as a result
of the annealing can be the structure of the sample, its weight (thermogravimetry,
TG), the heat flow during the annealing process (differential thermal analysis, DTA)
or the gaseous products emitted during the annealing. Each method can be performed
either in an inert atmosphere or in oxidizing media (air or pure oxygen). Thermal
measurements are typically performed in a controlled gas stream.
In the simplest case, the sample having a metastable structure undergoes some
structural relaxation and phase transformation upon annealing. The structure of the
sample can be detected with conventional diffractometric analysis at room temperature after particular periods (maximum temperatures and/or annealing times) after
which the samples are cooled again. In highly specific devices designed for in situ
structural observation, the diffraction pattern can be recorded at high temperature,
too.
While the diffractometric analysis of a sample series can give information on
the processes taking place, the threshold temperature of the structural transformation can seldom be established due to the limited number of samples treated. Since
the structural transformations are accompanied by some heat effect, its detection
during the annealing process offers a convenient tool to detect a collateral effect
of the structural transformation as a quazi-continuous function (i.e., measured with
frequently collected data point during the annealing process, not only by detecting