Deposition of Chromium on Iron

Trading Places Atomic-Style

This surreal landscape is actually an atomic-level view of chromium deposited on iron. The image was made by NIST researchers to better understand new magnetic recording and storage materials. Magnetic and non-magnetic metals can be stacked in very thin layers to make heads for reading magnetic data bits on computer disk drives. These "magneto-resistive" read heads can sense much smaller changes in magnetic direction than conventional heads. Consequently, magneto-resistive heads allow much denser packing of data on disk drives. The raised mesas in the scanning tunneling microscope picture above are composed of iron atoms, one layer thick, that have been displaced from the solid iron base material by the deposited chromium atoms. Using a special form of surface spectroscopy in conjunction with an STM built at NIST, the researchers were able to identify individual iron and chromium atoms. They found that the bumpy surface is formed by alternating atoms of chromium (peaks) and iron (valleys). This pattern indicates that the chromium is alloying with the iron during deposition, rather than simply laying on top. Such studies can help in optimizing methods for growing magnetic/non-magnetic layers in order to enhance the magneto-resistive response of read head materials.

Trading Places Atomic-Style

This surreal landscape is actually an atomic-level view of chromium deposited on iron. The image was made by NIST researchers to better understand new magnetic recording and storage materials.

Magnetic and non-magnetic metals can be stacked in very thin layers to make heads for reading magnetic data bits on computer disk drives. These "magneto-resistive" read heads can sense much smaller changes in magnetic direction than conventional heads. Consequently, magneto-resistive heads allow much denser packing of data on disk drives.

The raised mesas in the scanning tunneling microscope picture above are composed of iron atoms, one layer thick, that have been displaced from the solid iron base material by the deposited chromium atoms. Using a special form of surface spectroscopy in conjunction with an STM built at NIST, the researchers were able to identify individual iron and chromium atoms. They found that the bumpy surface is formed by alternating atoms of chromium (peaks) and iron (valleys). This pattern indicates that the chromium is alloying with the iron during deposition, rather than simply laying on top. Such studies can help in optimizing methods for growing magnetic/non-magnetic layers in order to enhance the magneto-resistive response of read head materials.