• Title/Summary/Keyword: $M{\ddot{o}}ssbauer$ source

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Collimator Design and Manufacture for $M{\ddot{o}}ssbauer$ Source ($M{\ddot{o}}ssbauer$ 선원용 콜리메이터 설계 및 제작)

  • Park, Sung-Ho;Kim, Jong-Kyung
    • Journal of Radiation Protection and Research
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    • v.28 no.3
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    • pp.183-187
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    • 2003
  • Collimator for $M{\ddot{o}}ssbauer$ source was manufactured for compton scattering experiment. Exposure dose rate was calculated and measured using GM counter for radiation evaluation. These results were well agreed to each other and used for collimator design. SUS303 was used for collimator material because exposure dose rate at 10 cm is about 2 mR/h. The radiation emited from the 35 mm, 65 mm hole was measured using gamma camera which have 4' diameter. 2-D radiation image was acquired and analyzed. The radiation size at Gamma Camera was 8.0 mm and 5.8 mm respectively.

Mössbauer Studies on Magnetoresistance in Chalcogenide Fe0.9M0.1Cr2S4 (M=Co, Ni, Zn) (Chalcogenide Fe0.9M0.1Cr2S4(M=Co, Ni, Zn)의 자기저항에 관한 Mössbauer 분광연구)

  • Park, Jae Yun;Lee, Byoung-Seob
    • Journal of the Korean Magnetics Society
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    • v.23 no.2
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    • pp.43-48
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    • 2013
  • The Jahn-Teller distortion of chalcogenide $Fe_{0.9}M_{0.1}Cr_2S_4$ (M=Co, Ni, Zn) have been investigated by M$\ddot{o}$ssbauer spectroscopy. The crystal structures of $Fe_{0.9}M_{0.1}Cr_2S_4$ (M=Co, Ni, Zn) are cubic spinel at room temperature. Magnetoresistance measurements indicate these system is conducting-semiconducting transistion around $T_C$. Below $T_C$, the asymmetric line broadening is observed and considered to be dynamic Jahn-Teller distortion. Isomer shift value of the samples at room temperature was about 0.5 mm/s, which means that charge state of Fe ions is ferrous in character. The Ni substitutions for Fe occur to increase the Jahn-Teller relaxation. CMR properties could be explained with magnetic polaron due to Jahn-Teller effect, which is different from both the double exchange interactions of manganite system and the triple exchange interactions of chalcogenide $Cu_xFe_{1-x}Cr_2S_4$.

Synthesis of Co Diffused Cu Matrix by Electroplating and Annealing for Application of Mössbauer Source (뫼스바우어선원적용을 위한 전기도금과 열처리기법을 이용한 Co가 확산된 Cu기지체 제조)

  • Choi, Sang Moo;Uhm, Young Rang
    • Journal of the Korean Magnetics Society
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    • v.24 no.6
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    • pp.186-190
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    • 2014
  • To establish the coating conditions for $^{57}Co$, non-radioactive Co ions are dissolved in an acid solution and electroplated on to a copper plate. Then, the thermal diffusion of electroplated Co into a copper matrix was studied to apply a $^{57}Co$ $M{\ddot{o}}ssbauer$ source. Nanocrystalline Co particles were coated on a Cu substrate using DC electro-deposition at a pH of 1.89 to 5 and $20{\sim}30mA/cm^2$. The average grain size was up to 54 nm as the pH increased to 5. The second phase of Co-oxide was formatted as the pH was increased above 4. The diffusion degree was evaluated by mapping using scanning electron microscopy (SEM). The influence of different annealing conditions was investigated. The diffusion depth of Co depends on the annealing temperature and time. The results obtained confirm that the deposited Co diffused almost completely into a copper matrix without substantial loss at an annealing temperature of $900^{\circ}C$ for 2 hours.