From ballistic transport to tunneling in electromigrated ferromagnetic breakjunctions.

TY - JOUR

T1 - From ballistic transport to tunneling in electromigrated ferromagnetic breakjunctions.

AU - Bolotin, Kirill I

AU - Kuemmeth, Ferdinand

AU - Pasupathy, Abhay N

AU - Ralph, D C

PY - 2006/1/1

Y1 - 2006/1/1

N2 - We fabricate ferromagnetic nanowires with constrictions whose cross section can be reduced gradually from 100 x 30 nm(2) to the atomic scale and eventually to the tunneling regime by means of electromigration. The contacts are mechanically and thermally stable. We measure low-temperature magnetoresistances (MR) <3% for contacts <400 Omega, reproducible MR variations that are nonmonotonic in the regime 400 Omega - 25 kOmega, and a maximum MR of 80% for atomic-scale widths. These results for devices > 400 Omega differ from previous room-temperature studies of electrodeposited devices. For samples in the tunneling regime, we observe large fluctuations in MR, between -10 and 85%.

AB - We fabricate ferromagnetic nanowires with constrictions whose cross section can be reduced gradually from 100 x 30 nm(2) to the atomic scale and eventually to the tunneling regime by means of electromigration. The contacts are mechanically and thermally stable. We measure low-temperature magnetoresistances (MR) <3% for contacts <400 Omega, reproducible MR variations that are nonmonotonic in the regime 400 Omega - 25 kOmega, and a maximum MR of 80% for atomic-scale widths. These results for devices > 400 Omega differ from previous room-temperature studies of electrodeposited devices. For samples in the tunneling regime, we observe large fluctuations in MR, between -10 and 85%.

U2 - 10.1021/nl0522936

DO - 10.1021/nl0522936

M3 - Journal article

SN - 1530-6984

VL - 6

SP - 123

EP - 127

JO - Nano Letters

JF - Nano Letters

IS - 1

ER -