Submillimeter Wave ESR of Cu(HCOO)2·4H2O in Pulsed High Magnetic Field

Electron paramagnetic resonance (EPR) and antiferromagnetic resonance (AFMR) of copper formate tetrahydrate (Cu(HCOO) 2 ·4H 2 O) is observed at 891 GHz (λ=0.337 mm) by using pulsed high magnetic fields up to 400 kOe. The parameters determined by Yamagata using Seehra and Castner's AFMR data well explain our experimental results in the antiferromagnetic state. From the temperatures at which linewidths show anomalies, the transition temperatures in high magnetic fields are estimated as T N ( H )=26±1, 35±5 and 30±2 K for H 0 // a '', b and c '', respectively. These are fairly high compared with the zero field T N of 17 K.

[1]  M. Date,et al.  Submillimeter Wave Magnetic Resonance of TMMC in Pulsed High Magnetic Field , 1984 .

[2]  T. Sakakibara,et al.  New problems on high-field magnetization in magnetic materials , 1983 .

[3]  Hidetarō Abe,et al.  Exchange and anisotropy parameters of Cu(HCOO)2·4H2O and Cu(HCOO)2·2Urea·2H2O , 1983 .

[4]  M. Motokawa.  HIGH FIELD ELECTRON SPIN RESONANCE IN THE SUBMILLIMETER REGION , 1983 .

[5]  T. Oguchi,et al.  Theory of the Field Dependence of the Néel Temperature in Quasi One-Dimensional Antiferromagnets , 1981 .

[6]  I. Harada,et al.  Experimental and Theoretical Study of the Phase Diagram of the Linear Antiferromagnet (CH3)4NMnCl3 (TMMC) , 1980 .

[7]  Y. Endoh,et al.  A Field Induced Antiferromagnetic Order in Cu(HCOO)2·4D2O above TN , 1978 .

[8]  I. Yamamoto,et al.  EPR g-Shift and Anisotropic Magnetic Susceptibility in K 2 MnF 4 , 1977 .

[9]  K. Yamagata,et al.  Proton Resonance Study of the Antiferromagnetic State of Two-Dimensional Cu(HCOO)2·4D2O , 1977 .

[10]  Y. Ajiro,et al.  A large NMR lineshift due to induced-staggered magnetization in paramagnetic state , 1976 .

[11]  E. Fenton.  Free phase angle of the single-Q state in chromium , 1976 .

[12]  Y. Ajiro,et al.  Crystallographic Two Sublattice System –Staggered Susceptibility and Induced Staggered Magnetization in Paramagnetic State– , 1976 .

[13]  Y. Kozuka,et al.  Angular Dependence of the Magnetization Curve in a Two-Dimensional Antiferromagnet: Cu(HCOO)2·4H2O , 1976 .

[14]  K. Nagata.  Short Range Order Effects on EPR Frequencies in Antiferromagnets with Inequivalent g-Tensors , 1976 .

[15]  T. Haseda,et al.  Heat Capacity of Cu(HCOO)2·4H2O at Magnetic Transition Temperature , 1975 .

[16]  K. Nagata,et al.  Short Range Order Effects on EPR Frequencies in Heisenberg Linear Chain Antiferromagnets , 1972 .

[17]  M. Date,et al.  Anomalous Shift of ESR Lines in Two Dimensional Antiferromagnet Cu(HCOO)24H2O , 1970 .

[18]  M. Seehra,et al.  Study of the Ordered Magnetic State of Copper Formate Tetrahydrate by Antiferromagnetic Resonance , 1970 .

[19]  Muneyuki,et al.  Short Range Order Effect in Paramagnetic Resonance Line Width of CuF22H2O , 1964 .

[20]  H. Mori.  Paramagnetic resonance line width in antiferromagnets. , 1963 .

[21]  Hanako Kobayashi,et al.  The Magnetic Properties of Cupric Formate Tetrapydrate at Low Temperatures , 1963 .

[22]  K. Ōno,et al.  Paramagnetic Resonance Absorption in Copper Formate , 1956 .