Reversible Mn segregation at the polar surface of lithium tetraborate

Authors

Christina Dugan, Air Force Institute of Technology
Robert L. Hengehold, Air Force Institute of Technology
Steve R. McHale, Air Force Institute of TechnologyFollow
Juan A. Colon Santana, University of Nebraska-Lincoln
John W. McClory, Air Force Institute of Technology
V T. Adamiv, Institute of Physical Optics
Ya V. Burak, Institute of Physical Optics
Yaroslav B. Losovyj, University of Nebraska-LincolnFollow
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

2013

Citation

APPLIED PHYSICS LETTERS 102 (2013)

Comments

U.S. Government work

Abstract

We find Mn surface segregation for single crystals of Mn doped Li₂B₄O₇, nominally Li_1.95Mn_0.05 B₄O₇(001), but as the temperature increases, evidence of this Mn surface segregation diminishes significantly. At room temperature, the surface photovoltaic charging is significant for this pyroelectric material but is quenched at a temperature well below that seen for the undoped Li₂B₄O₇ samples. The suppression of surface charging in the region of 120°C that accompanies the temperature of Mn dissolution in the bulk of Li₂B₄O₇, i.e., the reversal of Mn surface segregation (215°C), suggests that along the (001) direction, ionic transport must be considered as significant.