DMEGC introduces new power materials DMR51W & DMR52W, which have even further reduced power losses at high temperatures and high frequencies. Optimal frequency range of DMR51W is 0.5MHz to 2MHz and 1.5MHZ to 5MHz for DMR52W. Where space is an issue, you can gain that extra room in your design by using DMR51W and DMR52W ferrite material.

You can find material data here: 

DMR52W Material Characteristics-REV A

DMR51W-REV.B Material Characteristics