|   |   |   |   |   |  | webmail : intra-extraAccès VPN |  Accès IST |  Contact | English
Univ. Paris-Saclay
Unusual island formations of silver and iridium on germanium studied by LEEM and STM
  - STM and LEEM Group - UC Davis
Vendredi 30/03/2012, 11:00
SPEC Bât 466 p.111 (1er ét.), CEA-Saclay

Shirley Chiang est invitée par Patrick Soukiassian,

Abstract :

The growth of silver deposited on Ge(110) was studied with low energy electron microscopy (LEEM) and scanning tunneling microscopy (STM). LEEM movies showed the formation of long, one-dimensional islands as Ag was deposited above 700K, with island nucleation proceeding from defects in the Ge substrate. During deposition, the length of the islands increased while the width remained constant, with island size and distribution dependent on substrate temperature. At 750K, islands were 100 nm wide and 1-20 microns long at 9 ML of coverage. STM images showed that the islands were composed of Ag and that the surface regions between the islands exhibited a reconstruction which is characteristic of pure Ge.

STM was used to characterize the growth of iridium onto the Ge(111) c(2x8) surface at different coverages less than 1ML, with samples annealed to temperatures between 550K and 750K. A new form of growth was observed, consisting of pathways connecting larger iridium islands. As the annealing temperature increased, the iridium growth first formed unusual shapes with finger-like protrusions.  Next, these shapes broke apart into smaller islands, which ultimately formed into larger islands at higher temperatures. High resolution images were obtained, allowing insight into the atomic arrangements. We have also done simulations of the growth process, which give insight into the origins of this unusual growth behavior.

We also used LEEM to study the growth of, and transformations between the (4x4), (√3x√3)R30°, and (3x1) structural phases of Ag deposited on Ge(111) both below and above the Ag desorption temperature of 850K.


http://www.physics.ucdavis.edu/stm/stm.htm
Contact : Cindy ROUNTREE

 

Séminaire SPCSI - Informations pratiques

Entrée sur le site du CEA de Saclay pour les séminaires SPCSI

Afin de pouvoir entrer sur le site du CEA de Saclay veuillez adresser les données personnelles suivantes par courriel à Christine Prigian et Catherine Julien (secrétariat) un avis d’entrée vous sera alors délivré:

 

Nom:

 

 

Prénom:

Date et lieu de naissance:

Nationalité:

Nom de l'employeur:

 

Ces informations doivent être envoyées au mieux deux jours avant la date du séminaire.

Lors de votre venue vous devez vous présenter avec une carte d'identité ou un passeport en cours de validité. L'entrée sur le site se fait par l'entrée principale ou porte Nord (suivre le lien ci-dessous), un badge vous y sera remis. Demandez à l'accueil le Bât.466, ils vous renseigneront.
Les séminaires se déroulent au Bât. 466, pièce 111 (1er étage).
En cas de problème vous pouvez contacter le secrétariat au : 01 69 08 65 32 /  40 12.


Formalities for entering the CEA Saclay site for SPCSI seminars

 

 

To enter in CEA Saclay you need to send the following personal data to Christine  PRIGIAN and Catherine Julien (secretariat):

 

 

Informations utiles/Practical informations - Contact

Informations:  Access



 

Contact: Christine Prigian et Catherine Julien

 

Last Name :

First Name :

Place and date of birth :

Nationality :

Employer Name :

These informations must be preferably sent at least two days before the seminar date.

 

When you come you must have a valid ID card or passport with you.

The entrance in CEA Saclay is through the main entrance or north entrance (see link below), a pass will be delivered. Ask at the “accueil” the path for the building 466. SPCSI seminars take place in room 111 (first floor).

Any questions/troubles do not hesitate to contact our secretariat : 33 (0)1 69 08 65 32 /  40 12.

#28 - Mise à jour : 0000-00-00 00:00:00

 

Retour en haut