Quantifying Intrinsic, Extrinsic, Dielectric, and Secondary Pyroelectric Responses in PbZr_1–xTi_xO₃ Thin Films

Journal Article · Wed Sep 04 00:00:00 EDT 2019 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/acsami.9b12191· OSTI ID:1633244

Velarde, Gabriel ^[1]; Pandya, Shishir ^[1]; Zhang, Lei ^[1]; Garcia, David ^[1]; Lupi, Eduardo ^[1]; Gao, Ran ^[1]; Wilbur, Joshua D. ^[1]; Dames, Chris ^[1]; Martin, Lane W. ^[2]

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1. Univ. of California, Berkeley, CA (United States)
2. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Applications such as solid-state waste-heat energy conversion, infrared sensing, and thermally-driven electron emission rely on pyroelectric materials (a subclass of dielectric piezoelectrics) which exhibit temperature-dependent changes in polarization. Although enhanced dielectric and piezoelectric responses are typically found at polarization instabilities such as temperature- and chemically induced phase boundaries, large pyroelectric effects have been primarily limited in study to temperature-induced phase boundaries. Here in this paper, we directly identify the magnitude and sign of the intrinsic, extrinsic, dielectric, and secondary pyroelectric contributions to the total pyroelectric response as a function of chemistry in thin films of the canonical ferroelectric PbZr$$_{1-x}$$Ti$$_x$$O$$_3$$ (x = 0.40, 0.48, 0.60, and 0.80) across the morphotropic phase boundary. Using phase-sensitive frequency and applied dc-bias methods, the various pyroelectric contributions were measured. It is found that the total pyroelectric response decreases systematically as one moves from higher to lower titanium contents. This arises from a combination of decreasing intrinsic response (-232 to -97 μC m$$^{-2}$$ K$$^{-1}$$) and a sign inversion (+33 to -17 μC m$$^{-2}$$ K$$^{-1}$$)) of the extrinsic contribution upon crossing the morphotropic phase boundary. Additionally, the measured secondary and dielectric contributions span between -70 and -29 and 10-115 μC m$$^{-2}$$K$$^{-1}$$) under applied fields, respectively, following closely trends in the piezoelectric and dielectric susceptibility. These findings and methodologies provide novel insights into the understudied realm of pyroelectric response.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1633244
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 38 Vol. 11; ISSN 1944-8244; ISSN 1944-8252
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PbZr1−xTixO3
ferroelectric
morphotropic phase boundary
pyroelectric
thin films