We report the successful growth and characterization of Li_9Cr_3(P_2O_7)_3(PO_4)_2single crystal,and investigate its magnetic properties under external magnetic fields via magnetization and heat capacity measurements....We report the successful growth and characterization of Li_9Cr_3(P_2O_7)_3(PO_4)_2single crystal,and investigate its magnetic properties under external magnetic fields via magnetization and heat capacity measurements.Our study reveals that Li_9Cr_3(P_2O_7)_3(PO_4)_2 is an easy-plane kagome ferromagnet with S=3/2,as evidenced by the Curie–Weiss temperature of 6 K which implies a ferromagnetic exchange coupling in the material.Under zero magnetic field,Li_9Cr_3(P_2O_7)_3(PO_4)_2 undergoes a magnetic transition at TC=2.7 K from a paramagnetic state to a ferromagnetically ordered state with the magnetic moment lying in the kagome plane.By applying a c-axis directional magnetic field to rotate the spin alignment from the kagome plane to the c-axis,we observe a reduction in the magnetic transition temperature as the field is increased.We construct a magnetic phase diagram as a function of temperature and magnetic field applied parallel to the c-axis of Li_9Cr_3(P_2O_7)_3(PO_4)_2 and find that the phase boundary is linear over a certain temperature range.Regarding that theoretically,the field-induced phase transition of the spin reorientation in the easy-plane ferromagnet can be viewed as the ferromagnetic magnon Bose–Einstein condensation(BEC),the phase boundary scaling of field-induced(B c)magnetic transition in Li_9Cr_3(P_2O_7)_3(PO_4)_2 can be described as the quasi-2D magnon BEC,which has been observed in other ferromagnetic materials such as K_2CuF_4.展开更多
The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by t...The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by the hydrothermal method.LnCu_(3)(OH)_(6)Cl_(3) adopts space group P3m1 and features the layered Cu-kagome lattice with lanthanide Ln3+cations sitting at the center of the hexagons.Although heavy lanthanides(Ln=Gd,Tb,Dy)in LnCu_(3)(OH)_(6)Cl_(3) provide a large effective magnetic moment and ferromagnetic-like spin correlations compared to light-lanthanides(Nd,Sm,Eu)analogues,Cu-kagome holds an antiferromagnetically ordered state at around 17 K like YCu_(3)(OH)_(6)Cl_(3).展开更多
基金Shenzhen Fundamental Research Program(Grant No.JCYJ20220818100405013)。
文摘We report the successful growth and characterization of Li_9Cr_3(P_2O_7)_3(PO_4)_2single crystal,and investigate its magnetic properties under external magnetic fields via magnetization and heat capacity measurements.Our study reveals that Li_9Cr_3(P_2O_7)_3(PO_4)_2 is an easy-plane kagome ferromagnet with S=3/2,as evidenced by the Curie–Weiss temperature of 6 K which implies a ferromagnetic exchange coupling in the material.Under zero magnetic field,Li_9Cr_3(P_2O_7)_3(PO_4)_2 undergoes a magnetic transition at TC=2.7 K from a paramagnetic state to a ferromagnetically ordered state with the magnetic moment lying in the kagome plane.By applying a c-axis directional magnetic field to rotate the spin alignment from the kagome plane to the c-axis,we observe a reduction in the magnetic transition temperature as the field is increased.We construct a magnetic phase diagram as a function of temperature and magnetic field applied parallel to the c-axis of Li_9Cr_3(P_2O_7)_3(PO_4)_2 and find that the phase boundary is linear over a certain temperature range.Regarding that theoretically,the field-induced phase transition of the spin reorientation in the easy-plane ferromagnet can be viewed as the ferromagnetic magnon Bose–Einstein condensation(BEC),the phase boundary scaling of field-induced(B c)magnetic transition in Li_9Cr_3(P_2O_7)_3(PO_4)_2 can be described as the quasi-2D magnon BEC,which has been observed in other ferromagnetic materials such as K_2CuF_4.
基金supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (Grant No. 2017ZT07C062)Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices (Grant No. ZDSYS20190902092905285)+4 种基金Guangdong Basic and Applied Basic Research Foundation (Grant No. 2020B1515120100)the support of China Postdoctoral Science Foundation (Grant No. 2020M682780)the financial supports from Science and Technology Development Fund, Macao SAR, China (File No. 0051/2019/AFJ)Guangdong Basic and Applied Basic Research Foundation (Guangdong-Dongguan Joint Fund No. 2020B1515120025)Guangdong–Hong Kong–Macao Joint Laboratory for Neutron Scattering Science and Technology, China (Grant No. 2019B121205003)
文摘The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by the hydrothermal method.LnCu_(3)(OH)_(6)Cl_(3) adopts space group P3m1 and features the layered Cu-kagome lattice with lanthanide Ln3+cations sitting at the center of the hexagons.Although heavy lanthanides(Ln=Gd,Tb,Dy)in LnCu_(3)(OH)_(6)Cl_(3) provide a large effective magnetic moment and ferromagnetic-like spin correlations compared to light-lanthanides(Nd,Sm,Eu)analogues,Cu-kagome holds an antiferromagnetically ordered state at around 17 K like YCu_(3)(OH)_(6)Cl_(3).
