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A New Imaginary Term in the 2nd Order Nonlinear Susceptibility from Charged Interfaces

Ma, Emily and Ohno, Paul E. and Kim, Jeongmin and Liu, Yangdongling Dawning and Lozier, Emilie H. and Miller, Thomas F., III and Wang, Hong-Fei and Geiger, Franz M. (2021) A New Imaginary Term in the 2nd Order Nonlinear Susceptibility from Charged Interfaces. . (Unpublished)

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Non-resonant second harmonic generation phase and amplitude measurements obtained from the silica:water interface at varying pH and 0.5 M ionic strength point to the existence of a nonlinear susceptibility term, which we call chi(3)X, that is associated with a 90 deg phase shift. Including this contribution in a model for the total effective second-order nonlinear susceptibility produces reasonable point estimates for interfacial potentials and second-order nonlinear susceptibilities when chi(3)Xis about 1.5 times chi(3)water. A model without this term and containing only traditional chi(2) and chi(3) terms cannot recapitulate the experimental data. The new model also provides a demonstrated utility for distinguishing apparent differences in the second-order nonlinear susceptibility when the electrolyte is NaCl vs MgSO₄, pointing to the possibility of using HD-SHG to investigate ion-specificity in interfacial processes.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Ohno, Paul E.0000-0003-4192-1888
Miller, Thomas F., III0000-0002-1882-5380
Geiger, Franz M.0000-0001-8569-4045
Additional Information:Attribution 4.0 International (CC BY 4.0). P.E.O. gratefully acknowledges support from the NSF GRFP, the Schmidt Science Fellowship in partnership with the Rhodes Trust, and the Harvard University Center for the Environment. H.F.W. gratefully acknowledges support from the National Natural Science Foundation of China (NSFC Grant No. 21727802). T. F. M. and F.M.G. gratefully acknowledge support from the California Institute of Technology and Northwestern University, respectively.
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Schmidt Science FellowshipUNSPECIFIED
Harvard UniversityUNSPECIFIED
National Natural Science Foundation of China21727802
Northwestern UniversityUNSPECIFIED
Record Number:CaltechAUTHORS:20210412-101224507
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108694
Deposited By: Tony Diaz
Deposited On:12 Apr 2021 17:41
Last Modified:12 Apr 2021 17:41

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