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 This material is based upon work supported by the National Science Foundation, as part of the Center for Dielectrics and Piezoelectrics under Grant Nos. IIP-1361571 and IIP-1361503. The authors acknowledge the use of the Analytical Instrumentation Facility at NCSU, which is supported by the state of North Carolina and the National Science Foundation. M.J.C acknowledges support from the National Science Foundation, as part of NRT-SEAS under Grant No, DGE-1633587.