Journal of large-scale research facilities, 1, A24 (2015) http://dx.doi.org/10.17815/jlsrf-1-51

Published: 19.08.2015

PAES: Positron annihilation induced Auger
electron spectrometer

Heinz Maier-Leibnitz Zentrum
Technische Universität München

Instrument Scientists:
- Christoph Hugenschmidt, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München,

Garching, Germany, phone: +49(0) 89 289 14609, email: christoph.hugenschmidt@frm2.tum.de

Abstract: Positron annihilation induced Auger electron spectroscopy (PAES) is a newly developed
application for surface studies with high elemental selectivity and exceptional surface sensitivity. The
instrument is operated by the Technische Universität München and is located at NEPOMUC.

1 Introduction

In PAES, the emission of Auger electrons is initiated by positron-electron annihilation that leads to
several major advantages compared with conventional electron induced AES. The main features are:

• topmost layer sensitivity
• no secpndary electron background at the Auger peaks
• non-destructive technique

PAES is part of the surface spectrometer (SuSpect) which also enables sample preparation in UHV
conditions, conventaional AES and XPS. Examples for PAES studies are surfaces with sub-monolayers
of foreign atoms, high resolution determination of Auger line shapes, element selective surface studies.

2 Technical Data

2.1 Beam properties

• Positron implantation energy: E = 20 eV
• Electron energy resolution: ∆E/E < 1 %

1

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http://dx.doi.org/10.17815/jlsrf-1-51
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Journal of large-scale research facilities, 1, A24 (2015) http://dx.doi.org/10.17815/jlsrf-1-51

Figure 1: Instrument PAES, which is part of the surface spectrometer SuSpect at NEPOMUC (Copyright
by W. Schürmann, TUM).

2.2 Sample

• Sample size: ø 10 mm
• Sample thickness: 0.5 mm (0.1 - max. 3 mm)

2.3 Typical measurement times

• Measurement time (typical for one PAES spectrum): 10 – 15 min

2.4 Complementary techniques

• Electron or X-ray induced AES
• XPS
• STM

2

http://dx.doi.org/10.17815/jlsrf-1-51
https://creativecommons.org/licenses/by/4.0/

	Introduction
	Technical Data
	Beam properties
	Sample
	Typical measurement times
	Complementary techniques