AC-Susceptibility and SANS Studies of the Vortex States in V$_{-21at.\% }$Ti*

The vortex matter phase diagram of a binary alloy (V$_{-21at.\% }$Ti) has been mapped out using mutual-inductance ac susceptometry, and explored using small angle neutron scattering (SANS). In this sample, a peak effect (PE) appears at high fields, but disappears at low fields. The phase diagram shows a trend remarkably similar to that of a single-crystal \textit{Nb}, despite the vast differences in their respective values of \textbf{$\kappa $} and H$_{c2}$. SANS measurements of the vortex states in this sample shows the survival of quasi-long range order, suggesting the existence of a Bragg glass phase in this system. The SANS experiments were performed at the NIST Center For High Resolution Neutron Scattering (CHRNS).