Crystallographic and magnetic properties of CaLaMnMoO6 double perovskite

Powder neutron diffraction studies show that CaLaMnMoO6 double perovskite crystallizes in monoclinic P21/n  , with a=5.56961(9)a=5.56961(9), b=5.71514(9)b=5.71514(9), c=7.9358(1)Å and β=90.043(1)°β=90.043(1)°. Mn and Mo occupy the 2c and 2d positions, respectively, with 6.0(4)% Mn/Mo anti-site mixing. Temperature-dependent magnetic susceptibility measurements reveal that CaLaMnMoO6 is ferrimagnetic, with TN=92(3) K, below which large magnetic frustration is detected. The zero-field magnetic moment measured at 5 K is about 1.2 μB, comparable to that of ALaMnMoO6 (A=Ba and Sr), but much lower than expected for antiparallel ordering of formally Mn2+ (d5) and Mo5+ (d1). Moreover, no long-range magnetic ordering is observed in neutron diffraction data down to 4 K. The magnetic frustration is discussed in the framework of nearest-neighbors next-nearest-neighbors magnetic frustration.

Temperature-dependent magnetic susceptibility, χ and inverse susceptibility, 1/χ for the double perovskite, CaLaMnMoO6 at H=10kOe. Solid line is a fit of the ferrimagnetic modified Curie–Weiss model, 1/χ=T/C+1/χ0-σ/T-θ1/χ=T/C+1/χ0-σ/T-θ to the inverse susceptibility data.Figure optionsDownload as PowerPoint slide