Norgaard K, Eskildsen MR, Andersen NH, Jensen J, Hedegard P, Klausen SN, Canfield PC
Condensed Matter Physics and Chemistry Department, Riso National Laboratory, DK-4000 Roskilde, Denmark.
Phys Rev Lett. 2000 May 22;84(21):4982-5. doi: 10.1103/PhysRevLett.84.4982.
We have discovered a new antiferromagnetic phase in TmNi2B2C by neutron diffraction. The ordering vector is Q(A) = (0.48,0,0) and the phase appears above a critical in-plane magnetic field of 0.9 T. The field was applied in order to test the assumption that the zero-field magnetic structure at Q(F) = (0.094,0.094,0) would change into a c-axis ferromagnet if superconductivity were destroyed. We present theoretical calculations which show that two effects are important: a suppression of the ferromagnetic component of the RKKY exchange interaction in the superconducting phase and a reduction of the superconducting condensation energy due to the periodic modulation of the moments at Q(A).
我们通过中子衍射在TmNi2B2C中发现了一种新的反铁磁相。有序矢量为Q(A) = (0.48,0,0)，该相出现在0.9 T的临界面内磁场之上。施加该磁场是为了检验以下假设：如果超导性被破坏，Q(F) = (0.094,0.094,0)处的零场磁结构将转变为c轴铁磁体。我们给出的理论计算表明，有两个效应很重要：超导相中RKKY交换相互作用的铁磁分量受到抑制，以及由于Q(A)处磁矩的周期性调制导致超导凝聚能降低。
