Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. THz emission spectroscopy X-ray diffraction complex functional materials crystal structure depth profiling layered conducting transition metal oxides nickelates non-destructive characterization off-cut thin films resonant X-ray reflectivity superlattices terahertz generation thin film heterostructures transition-metal-oxide heterostructures transverse thermoelectric effect