Bombardi A, Rodriguez-Carvajal J, Di Matteo S, de Bergevin F, Paolasini L, Carretta P, Millet P, Caciuffo R
European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France.
Phys Rev Lett. 2004 Jul 9;93(2):027202. doi: 10.1103/PhysRevLett.93.027202. Epub 2004 Jul 7.
Powder neutron diffraction and resonant x-ray scattering measurements from a single crystal have been performed to study the low-temperature state of the 2D frustrated, quantum-Heisenberg system Li2VOSiO4. Both techniques indicate a collinear antiferromagnetic ground state, with propagation vector k=(1 / 2 1 / 2 0), and magnetic moments in the a-b plane. Contrary to previous reports, the ordered moment at 1.44 K, m=0.63(3)micro(B), is very close to the value expected for the square lattice Heisenberg model ( approximately 0.6micro(B)). The magnetic order is three dimensional, with antiferromagnetic a-b layers stacked ferromagnetically along the c axis. Neither x-ray nor neutron diffraction shows evidence for a structural distortion between 1.6 and 10 K.
已对单晶进行粉末中子衍射和共振X射线散射测量，以研究二维受挫量子海森堡体系Li2VOSiO4的低温状态。两种技术均表明存在共线反铁磁基态，其传播矢量k =(1 / 2 1 / 2 0)，且磁矩位于a - b平面内。与先前的报道相反，在1.44 K时的有序磁矩m = 0.63(3)玻尔磁子，非常接近正方形晶格海森堡模型预期的值（约0.6玻尔磁子）。磁序是三维的，反铁磁a - b层沿c轴铁磁堆叠。在1.6至10 K之间，X射线衍射和中子衍射均未显示出结构畸变的证据。
