Diffraction study of the crystal structures and phase transitions of double perovskites Sr₂MWO₆ (M= Ni,Zn,Co,Ca,Cd,Mg,Cu), SrLaMRuO₆ M= Mn,Cu,Ni,Co,Fe,Zn,Mg) and La₂NiRuO₆ (M=Ni,Zn,Co,Ca,Cd,Mg,Cu), SrLaMRuO₆ (M=Mn,Cu,Ni,Co,Fe,Zn,Mg) and La₂NiRuO₆