1 / 5

Half-Metallic Single Crystal CrO 2 Films (JHU MRSEC)

Half-Metallic Single Crystal CrO 2 Films (JHU MRSEC). Density of states. NM metal P = 0 . FM metal 0 < P < 1. Half Metal P = 1. Spintronic effects & devices depend directly on spin polarization P. (e.g., Cu) (e.g., Co) the ultimate. high R . low R. high R .

amos-noel
Download Presentation

Half-Metallic Single Crystal CrO 2 Films (JHU MRSEC)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Half-Metallic Single Crystal CrO2 Films (JHU MRSEC) Density of states NM metal P = 0 FM metal 0 < P < 1 Half Metal P = 1 Spintronic effects & devices depend directly on spin polarization P (e.g., Cu) (e.g., Co) the ultimate

  2. high R low R high R low R Spintronic effects & devices GMR Spin-valve GMR read-head MRAM TMR

  3. Half Metallic Ferromagnets The ultimate spin-polarized material Band structure of CrO2 • A single spin band • 100% spin polarized • Integer magnetic moment/unit cell • M = µB (nmajority - nminority) • nmajority + nminority = integer • nmajority = integer •  nmajority - nminority = integer • CrO2 (2 µB/unit cell) Crystal lattice of CrO2

  4. Single Crystal [100] CrO2 Films by CVD Point Contact Andreev Reflection • In ballistic (Sharvin) limit • l > a • Mean free path contact size CrO2 (P = 98.4%) is half metallic ! Ji, Strijkers, Yang, Chien, Byers, Anguelouch, Xiao, and Gupta, Phys. Rev. Lett. 86, 5585 (2001). Anguelouch, Gupta, Xiao, Abraham, Ji, Ingvarsson, and Chien, Phys. Rev. B 64, 180408(R) (2001).

  5. Significance of Half-Metallic Ferromagnets • Ultimate magnetic tunnel junctions: infinite TMR Conducting Insulating • Perfect spin injector for semiconductors and metals • Physics of a single spin band

More Related