AVS 47th International Symposium
    Electronics Tuesday Sessions
       Session EL+NS-TuA

Paper EL+NS-TuA8
Quantized Conductance in AuPd Alloy Nanocontacts

Tuesday, October 3, 2000, 4:20 pm, Room 312

Session: Nanoelectronics
Presenter: A. Sakai, Kyoto University, Japan
Authors: A. Sakai, Kyoto University, Japan
A. Enomoto, Kyoto University, Japan
J. Sasaki, Kyoto University, Japan
S. Kurokawa, Kyoto University, Japan
Correspondent: Click to Email
Quantization of conductance can be observed most beautifully in Au nanocontacts but much less clearly in transition metals such as Pd. Then, an interesting problem is how the quantized conductance changes by alloying Au with Pd. Do all quantized peaks in the conductance histogram of Au disappear by a small amount of Pd, or do they survive even for Pd-rich nanocontacts? To answer this problem, we have carried out conductance measurements on AuPd nanocontacts in air at room temperature. We prepared Au@sub 1-x@Pd@sub x@ alloy wires with x = 20, 40, 50, 80, and 95 wt%, and measured the transient conductance at the break of two contacting wires. We find that the transition from the conductance behavior of Au to that of Pd takes place gradually with increasing the Pd concentration: sharp peaks in the histogram of Au are suppressed and replaced by a broad and featureless distribution observed in the histogram of Pd. At x = 40 and 50 wt%, both quantized peaks of Au and broad background of Pd coexist in a conductance histogram. This result implies that the conductance of AuPd nanocontacts becomes that of Au or Pd depending on which one of two constituent atoms occupies the narrowest constriction of the contact.