尖晶石结构自旋有序CaTi_2O_4单晶生长和磁化率特性研究  

Single crystal growth and magnetic properties of spinel structure and spin ordering compound CaTi_2 O_4

作　　者：刘雍[1] 周睿[1] 李靖[1] 张悦[1] 熊锐[1] 尹镝[1] 汤五丰[1] 石兢[1,2] 

机构地区：[1]武汉大学物理系,教育部声光材料与器件重点实验室,武汉430072 [2]中国科学院国际材料物理中心,沈阳110016

出　　处：《物理学报》2010年第8期5620-5625,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10974148;10674105);国家基础科学人才培养基金(批准号:J0830310)资助的课题~~

摘　　要：通过助溶剂熔融法并在氩气气氛炉中成功生长出高质量大尺寸的CaTi2O4的单晶.X射线衍射实验及能量损失谱EDS证实,制备的CaTi2O4单晶晶胞参数a=9.781A,b=9.966A,c=3.148A,所有样品均为单相,且符合化学计量比,样品高纯.通过直流磁化率的测量,首次给出了晶体的Van-Vleck顺磁因子为6.85×10-5cm3/mol,Cure-Weiss温度为-0.44K,呈弱反铁磁性.同时,通过单晶各向磁化率的测量,进一步确认了CaTi2O4晶体中一维有序Ti-Ti反铁磁dimer链的形成,并明确了其方向.High quality and large-size single crystals of CaTi2 O4 were prepared by the molten salt flux method. The X-ray diffraction and the EDS results showed that all the CaTi2 O4 crystals have the rom temperature lattice parameters a = 9. 781 A,b = 9. 966 A and c = 3. 148 A,and all the samples have perfect stoichiometric composition. Through the magnetic susceptibility measurement,we first obtained the Van-Vleck paramagnetic parameter of CaTi2 O4 of 6. 85 × 10 -5 cm3 /mol, and Cure-Weiss temperature of - 0. 44 K,revealing that CaTi2 O4 is a weak ferromagnetic compound. Further more,the existence of Ti-Ti dimer was confirmed by anisotropy measurement,the structure and direction of the antiferromagnetic dimer chains were also determined.

关 键 词：CaTi2O4 磁化率 各向异性 反铁磁二聚化 

分 类 号：O782[理学—晶体学] O737