Theory of electronic and magnetic properties of weak antiferromagnetic TiAu

To date, only a few itinerant magnetic compounds have been found, viz. ZrZn$_2$, TiBe$_2$ and Sr$_3$In, all comprised of nonmagnetic elements. TiAu, a newly synthesized itinerant weak antiferromagnet, orders antiferromagnetically below 36 K. Neutron diffraction reveals an ordered local moment of only 0.15 $\mu_B$/Ti at a wave vector Q=(0,$\pi$/b,0). Hole doping, viz. Ti$_{1-x}$Sc$_x$Au, causes the magnetic moment to disappear at a quantum critical point x$_{Sc}$=0.13. We present results of an extensive study of the electronic and magnetic properties of TiAu. DFT calculations reveal van Hove singularities at (0,0.45$\pi$/b,0.49$\pi$/c), 4 meV above the Fermi level. Several types of analysis will be discussed: fixed spin moment studies and Stoner enchancement; magnetic energies; magnetism versus doping; Fermi surface nesting; corrections for spin fluctuations.