The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4....The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4.96 K. The moment of 2.16#B per Co at 1.6K in the screw chain running along the c axis Mternates in the c axis. The moments of neighboring screw chains are arranged antiferromagnetically along one in-plane axis and ferromagnetieally Monk the other in-plane axis. This magnetic configuration breaks the four-fold symmetry of the tetragonM crystal structure and leads to two equally populated magnetic twins with the antiferromagnetic vector in the a or b axis. The very similar magnetic state to the isostructural BaCo2 V~ 08 warrants SrCo2 V2 08 as another interesting half-integer spin-chain antiferromagnet for investigation on quantum antiferromagnetism.展开更多
Two new crystals of chlorovanadates,Ba_8Cs_5V_8O_（24）Cl_（13）（1） and MgCsV_2O_6Cl（2）,were grown in the molten salt media. 1 crystallizes in tetragonal,space group P4/mmm（No. 123）,with a = 14.801（2）,c = 12....Two new crystals of chlorovanadates,Ba_8Cs_5V_8O_（24）Cl_（13）（1） and MgCsV_2O_6Cl（2）,were grown in the molten salt media. 1 crystallizes in tetragonal,space group P4/mmm（No. 123）,with a = 14.801（2）,c = 12.341（3） ？,V = 2703.5（8） ？~3,Z = 2,Mr = 3015.56,F（000） = 2640,μ = 11.044 mm-1,Dc = 3.704 g/cm3,the final R = 0.0380 and wR = 0.0937 for 1654 observed reflections with I 〉 2σ（I）. 2 crystallizes in a monoclinic space group C2/c（No. 15） with a = 11.128（2）,b = 10.540（2）,c = 6.9892（14） ？,β = 118.38（3）°,V = 721.2（2） ？~3,Z = 4,M_r = 390.55,F（000） = 712,μ = 7.997 mm-1,D_c = 3.597 g/cm^3,the final R = 0.0537 and w R = 0.1363 for 740 observed reflections with I 〉 2σ（I）. 1 exhibits a novel 8-membered-ring [V_8O_（24）] consisting of 8 corner-shared VO_4 tetrahetra,but in 2,an infinite ladder-like [VO_3]_∞ chain is formed by VO_5 square pyramids through sharing the edges.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921700 and 2011CBA00112the National Natural Science Foundation of China under Grant Nos 11034012 and 11190024
文摘The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4.96 K. The moment of 2.16#B per Co at 1.6K in the screw chain running along the c axis Mternates in the c axis. The moments of neighboring screw chains are arranged antiferromagnetically along one in-plane axis and ferromagnetieally Monk the other in-plane axis. This magnetic configuration breaks the four-fold symmetry of the tetragonM crystal structure and leads to two equally populated magnetic twins with the antiferromagnetic vector in the a or b axis. The very similar magnetic state to the isostructural BaCo2 V~ 08 warrants SrCo2 V2 08 as another interesting half-integer spin-chain antiferromagnet for investigation on quantum antiferromagnetism.
基金supported by the National Natural Science Foundation of China(No.21541009)
文摘Two new crystals of chlorovanadates,Ba_8Cs_5V_8O_（24）Cl_（13）（1） and MgCsV_2O_6Cl（2）,were grown in the molten salt media. 1 crystallizes in tetragonal,space group P4/mmm（No. 123）,with a = 14.801（2）,c = 12.341（3） ？,V = 2703.5（8） ？~3,Z = 2,Mr = 3015.56,F（000） = 2640,μ = 11.044 mm-1,Dc = 3.704 g/cm3,the final R = 0.0380 and wR = 0.0937 for 1654 observed reflections with I 〉 2σ（I）. 2 crystallizes in a monoclinic space group C2/c（No. 15） with a = 11.128（2）,b = 10.540（2）,c = 6.9892（14） ？,β = 118.38（3）°,V = 721.2（2） ？~3,Z = 4,M_r = 390.55,F（000） = 712,μ = 7.997 mm-1,D_c = 3.597 g/cm^3,the final R = 0.0537 and w R = 0.1363 for 740 observed reflections with I 〉 2σ（I）. 1 exhibits a novel 8-membered-ring [V_8O_（24）] consisting of 8 corner-shared VO_4 tetrahetra,but in 2,an infinite ladder-like [VO_3]_∞ chain is formed by VO_5 square pyramids through sharing the edges.
