Magnetic recording media having improved magnetic properties such as an improved signal-to-noise ratio. The recording media includes a magnetic recording layer and an underlayer disposed beneath the magnetic recording layer. The underlayer is a Cr-based alloy such as CrMo that includes an additive selected from boron (B), silicon (Si) and boron nitride (BN). The additive preferentially segregates to the grain boundaries in the underlayer to reduce the grain size and grain size distribution in the underlayer.