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Title: Low work function in the 122-family of iron-based superconductors

Abstract

Herein we determine the work functions of the iron arsenic compounds A Fe 2 As 2 ( A = Ca , Ba , Cs ) using photoemission spectroscopy to be 2.7 eV for CaFe 2 As 2 , 1.8 eV for BaFe 2 As 2 , and 1.3 eV for CsFe 2 As 2 . The work functions of these 122 iron-based superconductors track those of the elementary metal A but are substantially smaller. The most likely explanation of this observation is that the cleaving surface exposes only half an A -layer. The low work function and good photoemission cross section of BaFe 2 As 2 and CsFe 2 As 2 enable photoemission even from a common white LED light.

Authors:
ORCiD logo [1];  [2];  [3];  [3];  [4];  [3];  [3];  [5];  [5];  [6];  [4]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Tel Aviv Univ., Ramat Aviv (Israel)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Stanford Univ., CA (United States). Geballe Lab. for Advanced Materials
  4. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
  5. Nanjing Univ. (China)
  6. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Stanford Univ., CA (United States). Geballe Lab. for Advanced Materials and Dept. of Physics
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Sponsoring Org.:
Alexander von Humboldt Foundation; German Science Foundation (DFG); Gabilan Stanford Graduate Fellowship; National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1605595
Alternate Identifier(s):
OSTI ID: 1603199
Grant/Contract Number:  
AC02-76SF00515; DGE-114747; AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 4; Journal Issue: 3; Journal ID: ISSN 2475-9953
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE

Citation Formats

Pfau, H., Soifer, H., Sobota, J. A., Gauthier, A., Rotundu, C. R., Palmstrom, J. C., Fisher, I. R., Chen, G.-Y., Wen, H.-H., Shen, Z.-X., and Kirchmann, P. S. Low work function in the 122-family of iron-based superconductors. United States: N. p., 2020. Web. doi:10.1103/PhysRevMaterials.4.034801.
Pfau, H., Soifer, H., Sobota, J. A., Gauthier, A., Rotundu, C. R., Palmstrom, J. C., Fisher, I. R., Chen, G.-Y., Wen, H.-H., Shen, Z.-X., & Kirchmann, P. S. Low work function in the 122-family of iron-based superconductors. United States. doi:https://doi.org/10.1103/PhysRevMaterials.4.034801
Pfau, H., Soifer, H., Sobota, J. A., Gauthier, A., Rotundu, C. R., Palmstrom, J. C., Fisher, I. R., Chen, G.-Y., Wen, H.-H., Shen, Z.-X., and Kirchmann, P. S. Wed . "Low work function in the 122-family of iron-based superconductors". United States. doi:https://doi.org/10.1103/PhysRevMaterials.4.034801. https://www.osti.gov/servlets/purl/1605595.
@article{osti_1605595,
title = {Low work function in the 122-family of iron-based superconductors},
author = {Pfau, H. and Soifer, H. and Sobota, J. A. and Gauthier, A. and Rotundu, C. R. and Palmstrom, J. C. and Fisher, I. R. and Chen, G.-Y. and Wen, H.-H. and Shen, Z.-X. and Kirchmann, P. S.},
abstractNote = {Herein we determine the work functions of the iron arsenic compounds AFe2As2 (A=Ca,Ba,Cs) using photoemission spectroscopy to be 2.7 eV for CaFe2As2, 1.8 eV for BaFe2As2, and 1.3 eV for CsFe2As2. The work functions of these 122 iron-based superconductors track those of the elementary metal A but are substantially smaller. The most likely explanation of this observation is that the cleaving surface exposes only half an A-layer. The low work function and good photoemission cross section of BaFe2As2 and CsFe2As2 enable photoemission even from a common white LED light.},
doi = {10.1103/PhysRevMaterials.4.034801},
journal = {Physical Review Materials},
number = 3,
volume = 4,
place = {United States},
year = {2020},
month = {3}
}

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