Singlet Ground State and Combined Electron-Nuclear Magnetism in Praseodymium

Abstract

Comprehensive neutron scattering1 and magnetisation studies2 have established that the ions in double hcp Pr metal experience a crystalline electric field which splits the 3H4 ground multiplet to produce singlet ground states at both the locally hexagonal and cubic sites. For singlet ground state systems to exhibit magnetic ordering as T→O, the exchange coupling J(q) must exceed a threshold value, expressed by the condition η = 4α2J(q)/∆ > 1 where ∆ and α denote the energy separation and matrix element between ground and excited states respectively3. Pr provides a canonical example of such a singlet ground state system.KeywordsUniaxial StressLongitudinal OpticTransverse OpticReciprocal Lattice PointCrystalline Electric FieldThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.