Demonstration of NV-detected <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">C</mml:mi><mml:mprescripts /><mml:none /><mml:mn>13</mml:mn></mml:mmultiscripts></mml:math> NMR at 4.2 T

The nitrogen-vacancy (NV) center in diamond has enabled studies of nanoscale nuclear magnetic resonance (NMR) and electron paramagnetic with high sensitivity small sample volumes. Most NV-detected NMR (NV-NMR) experiments are performed at low fields. While fields useful many applications, high-field NV-NMR fine spectral resolution, signal sensitivity, the capability to observe a wider range nuclei is advantageous for surface detection, microfluidic, condensed matter aimed probing micro- features. However, only handful above 1 T were reported. Herein, we report $^{13}$C spectroscopy 4.2 T, where NV Larmor frequency 115 GHz. Using an electron-nuclear double technique, successfully detect two samples. analysis linewidth based on dipolar broadening theory Van Vleck shows that observed linewidths from consistent intrinsic sample. For 2 find narrower 44 ppm. This work paves way new applications NV-NMR.