The Kondo effect in amorphous

Abstract

We present conductivity data for a range of a- films on the metallic side of the metal - insulator transition. In the temperature range T = 20 - 200 K, electron - electron interaction and weak-localization effects are identified, with the temperature dependence of the latter resulting from inelastic electron - electron scattering. At lower temperatures, we have observed a deviation from the high-T behaviour towards higher resistance. This effect is attributed to Kondo-type s - d exchange scattering of conduction electrons by Mn spins.

Quenched magnetic moment in Mn-doped amorphous Si (\textit{a}-Mn$_{x}$Si$_{1-x}$) across the metal-insulator transition

“…There have been limited reports about Mn-implanted a-Si (denoted as a-Si 1−x :Mn x ), mainly focusing on transport properties for x∼0.07-0.22 [21,22,23]. Samples were prepared by room-temperature Mn ion-implantation either into e-beam-evaporated a-Si on quartz (x≤0.13) [21] or into c-Si on sapphire with simultaneous amorphization of the films (x>0.13) [22]. No magnetic properties were reported.…”

Quenched magnetic moment in Mn-doped amorphous Si films

“…Therefore, it is intriguing that the few reports on magnetotransport of Mnimplanted a-Si samples ͑a-Si 1−x :Mn x , x ϳ 0.07-0.22͒ showed no large negative MR effect; magnetic properties were not reported. [19][20][21] In this Brief Report, we describe a systematic magnetization and magnetotransport study on Mn-doped a-Si ͑a-Mn x Si 1−x ͒ films ͑where x ranges from 5 ϫ 10 −3 to 0.175͒, covering both the dilute region and the M-I transition region. Films were grown by e-beam coevaporation from Si and Mn sources onto substrates held near room temperature under ultrahigh-vacuum conditions ͑base pressure of ϳ8 ϫ 10 −10 Torr͒.…”