skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Imaging anomalous nematic order and strain in optimally doped BaFe$$_2$$(As,P)$$_2$$

Abstract

We present the strain and temperature dependence of an anomalous nematic phase in optimally doped BaFe$$_2$$(As,P)$$_2$$. Polarized ultrafast optical measurements reveal broken 4-fold rotational symmetry in a temperature range above $$T_c$$ in which bulk probes do not detect a phase transition. Using ultrafast microscopy, we find that the magnitude and sign of this nematicity vary on a $${50{-}100}~\mu$$m length scale, and the temperature at which it onsets ranges from 40 K near a domain boundary to 60 K deep within a domain. Scanning Laue microdiffraction maps of local strain at room temperature indicate that the nematic order appears most strongly in regions of weak, isotropic strain. These results indicate that nematic order arises in a genuine phase transition rather than by enhancement of local anisotropy by a strong nematic susceptibility. We interpret our results in the context of a proposed surface nematic phase.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [2];  [1];  [1]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Div.
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1440954
DOE Contract Number:
AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: arXiv.org Repository; Journal Volume: 2017
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Thewalt, Eric, Hayes, Ian M., Hinton, James P., Little, Arielle, Patankar, Shreyas, Wu, Liang, Helm, Toni, Stan, Camelia V., Tamura, Nobumichi, Analytis, James G., and Orenstein, Joseph. Imaging anomalous nematic order and strain in optimally doped BaFe$_2$(As,P)$_2$. United States: N. p., 2017. Web.
Thewalt, Eric, Hayes, Ian M., Hinton, James P., Little, Arielle, Patankar, Shreyas, Wu, Liang, Helm, Toni, Stan, Camelia V., Tamura, Nobumichi, Analytis, James G., & Orenstein, Joseph. Imaging anomalous nematic order and strain in optimally doped BaFe$_2$(As,P)$_2$. United States.
Thewalt, Eric, Hayes, Ian M., Hinton, James P., Little, Arielle, Patankar, Shreyas, Wu, Liang, Helm, Toni, Stan, Camelia V., Tamura, Nobumichi, Analytis, James G., and Orenstein, Joseph. Fri . "Imaging anomalous nematic order and strain in optimally doped BaFe$_2$(As,P)$_2$". United States. doi:.
@article{osti_1440954,
title = {Imaging anomalous nematic order and strain in optimally doped BaFe$_2$(As,P)$_2$},
author = {Thewalt, Eric and Hayes, Ian M. and Hinton, James P. and Little, Arielle and Patankar, Shreyas and Wu, Liang and Helm, Toni and Stan, Camelia V. and Tamura, Nobumichi and Analytis, James G. and Orenstein, Joseph},
abstractNote = {We present the strain and temperature dependence of an anomalous nematic phase in optimally doped BaFe$_2$(As,P)$_2$. Polarized ultrafast optical measurements reveal broken 4-fold rotational symmetry in a temperature range above $T_c$ in which bulk probes do not detect a phase transition. Using ultrafast microscopy, we find that the magnitude and sign of this nematicity vary on a ${50{-}100}~\mu$m length scale, and the temperature at which it onsets ranges from 40 K near a domain boundary to 60 K deep within a domain. Scanning Laue microdiffraction maps of local strain at room temperature indicate that the nematic order appears most strongly in regions of weak, isotropic strain. These results indicate that nematic order arises in a genuine phase transition rather than by enhancement of local anisotropy by a strong nematic susceptibility. We interpret our results in the context of a proposed surface nematic phase.},
doi = {},
journal = {arXiv.org Repository},
number = ,
volume = 2017,
place = {United States},
year = {Fri Sep 22 00:00:00 EDT 2017},
month = {Fri Sep 22 00:00:00 EDT 2017}
}