Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the C...Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the Cu-DTN is of a tetrahedral structure with lattice parameter c being 9.0995 A, which is 1.32% expansion compared with that of parent material DTN due to the larger radius of the Cu ion. Direct current（DC） susceptibility measurements show that both the antiferromagnetic exchange interaction at low temperature and the large anisotropy of susceptibilities are suppressed after doping the Cu ion, which could be related to the structural distortion and the increase of the super-exchange paths in Cu-DTN.展开更多
Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Mo...Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.展开更多
<正> Two new binuclear copper（Ⅱ） complexes, [Cu（oxpn）CuL]（ClO4）2, have been synthesizedand characterized, where oxpn is N,N’ bis（3-aminopropyl）oxamido and L is 1,10-phenan-throline （phen） or 5-nitro-...<正> Two new binuclear copper（Ⅱ） complexes, [Cu（oxpn）CuL]（ClO4）2, have been synthesizedand characterized, where oxpn is N,N’ bis（3-aminopropyl）oxamido and L is 1,10-phenan-throline （phen） or 5-nitro-1,10-phenanthroline （NO2-phen）. The crystal structure and vari-able-temperature magnetic susceptibility （4- 300 K） of the Complex （L=phen） have beendetermined. Crystal data: orthorhombic system, space group Pnma, with a = 10.433（1）, b11.458（2）, c = 21.999（2）A, z = 4. Every copper（Ⅱ） ion is in a square pyramidal environment.The two copper（Ⅱ） ions are linked by μ-oxamido bridge and the separation of them is 5.208A. The singlet-triplet energy gap J was found equal to -452.92cm-1, indicating that astrongantiferromagnetic spin-exchange interaction operates between the copper（Ⅱ） ions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404316 and 11304159)the Natural Science Foundation of Jiangsu Province+2 种基金Chinathe Science Foundation of Nanjing University of Posts and TelecommunicationsChina(Grant Nos.BK20140863 and NY213075)
文摘Single crystals of 4SC（NH2）2–Ni1-xCux Cl2（x = 0.03）（Cu-DTN） containing spin S = 1/2 Cu^2＋and S = 1 Ni^2＋cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the Cu-DTN is of a tetrahedral structure with lattice parameter c being 9.0995 A, which is 1.32% expansion compared with that of parent material DTN due to the larger radius of the Cu ion. Direct current（DC） susceptibility measurements show that both the antiferromagnetic exchange interaction at low temperature and the large anisotropy of susceptibilities are suppressed after doping the Cu ion, which could be related to the structural distortion and the increase of the super-exchange paths in Cu-DTN.
基金supported by the National Natural Science Foundation of China(Nos.21931008,21873072,21922304,and 21975184)the National Key R&D Program of China(No.2021YFA1200301)+2 种基金Fundamental Research Funds for the Central Universities,Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219)Natural Science Fund for Colleges and Universities in Jiangsu Province(No.22KJB150041)Wuxi"Taihu Light"Science and Technology Project-Basic Research(No.K20221067).
文摘Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.
基金Project supported by the National Natural Science Foundation of China.
文摘<正> Two new binuclear copper（Ⅱ） complexes, [Cu（oxpn）CuL]（ClO4）2, have been synthesizedand characterized, where oxpn is N,N’ bis（3-aminopropyl）oxamido and L is 1,10-phenan-throline （phen） or 5-nitro-1,10-phenanthroline （NO2-phen）. The crystal structure and vari-able-temperature magnetic susceptibility （4- 300 K） of the Complex （L=phen） have beendetermined. Crystal data: orthorhombic system, space group Pnma, with a = 10.433（1）, b11.458（2）, c = 21.999（2）A, z = 4. Every copper（Ⅱ） ion is in a square pyramidal environment.The two copper（Ⅱ） ions are linked by μ-oxamido bridge and the separation of them is 5.208A. The singlet-triplet energy gap J was found equal to -452.92cm-1, indicating that astrongantiferromagnetic spin-exchange interaction operates between the copper（Ⅱ） ions.
