Direct Measurement of the Electron Density at the Nucleus in Metallic Lithium at Liquid Helium Temperature

The nuclear polarization and electron spin resonance shift were observed in irradiated crystuls of lithium fluoride at a fnnquency of 9340 Mc/sec and at 4.2 to 1.5 tained K. A formula is given which relates the ESR shift to the nuclear magnetization, which in tunn is related to the electronic density. This value was found to be 0.442 combination rat 0.015, which compares favorably with theoretical and experimental values. (B. O.G.)