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고온에서 소결되는 고상 반응법 (OF)과 고온, 고압에서 소결하는 hot-forging (HF) 방법으로 DyMn$_2$O$_5$세라믹을 제조하고, 온도 (3 $\sim$ 300 K)와 자기장 (0 $\sim$ 9 T) 변화에 따른 DyMn$_2$O$_5$ 세라믹의 유전상수, 자발 분극, 비열 그리고 자기감수율을 측정하여 상전이 특성과 스핀과 결정상에 따른 강유전과 강자성 사이의 상호작용에 관하여 조사하였다. DyMn$_2$O$_5$ 세라믹은 42 K와 6 K에서 각각 Mn과 Dy에 의한 자기 상전이가 나타나며 26 K에서도 Mn에 의한 자기 상전이가 나타난다. 38 K에서는 incommensurate-commensurate에 기인하는 스핀 상태의 격자 주기와 commensurate 되면서 자기변형에 의한 결합 때문에 강유전성이 나오는 Curie 온도를 나타내는 강유전 상전이가 나타난다. DyMn$_2$O$_5$세라믹은 반강자성체로 6 K 에서 가장 큰 자기감수율 값 38 emu/g Oe을 나타내었다. DyMn$_2$O$_5$ 세라믹은 단결정의 모든 축방향에서 나타나는 평균값으로 측정되었으며 자기장이 5 T 인가되었을 때 약 5.8 $\mu_B$/f.u. 로 포화되었다. DyMn$_2$O$_5$ 세라믹의 유전상수는 38 K에서 가장 큰 피크를 나타내었으며, T$^{\prime}$$_{\rm N}$ = 26 K 아래에서 자기장에 따른 유전상수의 변화가 크게 나타났으며 자기장을 9 T 인가하였을 때 DyMn$_2$O$_5$ 세라믹의 유전상수 변형율은 15 \% 이었다.


We fabricated DyMn$_2$O$_5$ ceramics by using an ordinary firing (OF) and hot forging (HF) method and investigated the interaction between the ferroelectric and the ferromagnetic phases by analyzing the phase transition properties and the spin-crystal phase by measuring the magnetic polarization-magnetic field (M-H) curve, the specific heat, the magnetic susceptibility, and the dielectric constant as functions of the temperature (3 $\sim$ 300 K) and the magnetic field (0 $\sim$ 9 T). The DyMn$_2$O$_5$ ceramic exhibited magnetic phase transitions at 42 K and 6 K caused by Mn and Dy, respectively. The ferroelectric Curie temperature T$_{\rm C}$ was observed at 38 K. The DyMn$_2$O$_5$ ceramic showed an antiferroelectric characteristic with a large magnetic susceptibility of 38 emu/g Oe at 6 K. The magnetization of the DyMn$_2$O$_5$ ceramic saturated around 5.8 $\mu_B$/f.u. at 5 T. The dielectric constant of DyMn$_2$O$_5$ ceramic for various applied magnetic fields was represented by a high peak at 38 K. Below of T$^{\prime}$$_{\rm N}$ = 26 K, the dielectric constant changed rapid with increasing magnetic field and the dielectric constant effect attained 15 \% at an applied magnetic field of 9 T.


We fabricated DyMn$_2$O$_5$ ceramics by using an ordinary firing (OF) and hot forging (HF) method and investigated the interaction between the ferroelectric and the ferromagnetic phases by analyzing the phase transition properties and the spin-crystal phase by measuring the magnetic polarization-magnetic field (M-H) curve, the specific heat, the magnetic susceptibility, and the dielectric constant as functions of the temperature (3 $\sim$ 300 K) and the magnetic field (0 $\sim$ 9 T). The DyMn$_2$O$_5$ ceramic exhibited magnetic phase transitions at 42 K and 6 K caused by Mn and Dy, respectively. The ferroelectric Curie temperature T$_{\rm C}$ was observed at 38 K. The DyMn$_2$O$_5$ ceramic showed an antiferroelectric characteristic with a large magnetic susceptibility of 38 emu/g Oe at 6 K. The magnetization of the DyMn$_2$O$_5$ ceramic saturated around 5.8 $\mu_B$/f.u. at 5 T. The dielectric constant of DyMn$_2$O$_5$ ceramic for various applied magnetic fields was represented by a high peak at 38 K. Below of T$^{\prime}$$_{\rm N}$ = 26 K, the dielectric constant changed rapid with increasing magnetic field and the dielectric constant effect attained 15 \% at an applied magnetic field of 9 T.