Multiferroic materials exhibiting at least two ferroic orders are the subject of extensive research due to many potential technological applications. Bismuth ferrite (BFO) is by far the most studied multiferroicsince it exhibits room temperature magnetic and electric ordering. However, despite the potential of BFO there are many barriers to its commercial application. Researchers have been looking at ways to overcome these issues by replacing either the bismuth and/or iron in BFO. We have been exploring the solid solution between BFO and another technologically important material sodium niobate. Recent neutron diffraction data collected at room temperature shows that these materials are complex. We would now like to extend or initial study to look at the temperature dependence of four key compositions. This will allow us to complete the understanding of this phase diagram.