Evidence for Field-induced Topological Phase Transition in the Magnetically Frustrated Metal CePtAl₄Ge₂

Soohyeon Shin,Jin-Hong Park,Romain Sibille,Harim Jang,Taebeom Park,Suyong Kim,Tian Shang,Marisa Medarde,Eric D. Bauer,Oksana Zaharko,Michel Kenzelmann,Tuson Park 한국자기학회 2022 한국자기학회 학술연구발표회 논문개요집 Vol.32 No.2

Synthesis and pressure effects on the La doped CaFe2As2

Soohyeon Shin,T. Shang,H. Q. Yuan,Tuson Park 한국초전도저온학회 (구 한국초전도저온공학회) 2014 한국초전도저온공학회논문지 Vol.16 No.3

Synthesis and characterization of the heavy-fermion compound CePtAl₄Ge₂

Shin, Soohyeon,Rosa, Priscila F.S.,Ronning, Filip,Thompson, Joe D.,Scott, Brian L.,Lee, Sangyun,Jang, Harim,Jung, Soon-Gil,Yun, Eunbhin,Lee, Hyoyoung,Bauer, Eric D.,Park, Tuson Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.738 No.-

<P><B>Abstract</B></P> <P>We report the synthesis of the Ce-based quaternary compound CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> that crystallizes in the trigonal structure (space group <I>R</I> 3 ¯ <I>m</I>, 166) with unit cell parameters, <I>a</I> = 4.1995(5) Å, <I>c</I> = 31.851(7) Å, and γ = 120°. Powder X-ray diffraction and energy dispersive X-ray spectroscopy show that CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> (LaPtAl<SUB>4</SUB>Ge<SUB>2</SUB>) is in a single, homogeneous phase. Magnetic susceptibility, electrical resistivity, and heat capacity measurements of CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> show that it exhibits antiferromagnetic behavior below 2.3 K. The magnetic susceptibility for the magnetic field applied perpendicular (χ<SUB>ab</SUB>) and parallel (χ<SUB>c</SUB>) to the crystalline c-axis is very anisotropic, and the susceptibility ratio (χ<SUB>ab</SUB>/χ<SUB>c</SUB>) reaches a maximum value of 10, indicating that the spin easy axis is within the Ce plane. The entropy recovered at <I>T</I> <SUB>N</SUB> is consistent with the doublet ground state of the crystal field split <I>J</I> = 5/2 multiplet of Ce<SUP>3+</SUP> ions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> synthesized by the Al/Ge flux method adopts the trigonal structure. </LI> <LI> CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> is an antiferromagnet with <I>T</I> <SUB>N</SUB> of 2.3 K. </LI> <LI> CePtAl<SUB>4</SUB>Ge<SUB>2</SUB> is a heavy fermion compound with the effective mass of 205 mJ mol<SUP>−1</SUP> K<SUP>−2</SUP>. </LI> <LI> The entropy at <I>T</I> <SUB>N</SUB> is consistent with the doublet ground state of J = 5/2 of Ce<SUP>3+</SUP> ions. </LI> </UL> </P>

Synthesis and pressure effects on the La doped CaFe₂As₂

Shin, Soohyeon,Shang, T.,Yuan, H.Q.,Park, Tuson 한국초전도저온공학회 2014 한국초전도저온공학회논문지 Vol.16 No.3

We have synthesized La doped $CaFe_2As_2$ single crystals with Sn flux in an evacuated quartz ampule. Doping and pressure effects on the magnetic and superconducting properties of the under-doped $Ca_{1-x}La_xFe_2As_2$ (x=0.08, 0.1) were studied by measuring electrical resistivity under quasi-hydrostatic pressure up to 21 kbar. Magnetic transition temperatures for all studied concentrations were sharply suppressed with slight amplitude of pressure, less than 3 kbar, while superconducting transition temperatures were robust against pressure. In this communication, we report temperature-pressure phase diagram for the La-doped $CaFe_2As_2$ single crystals.

Apical surgery in conjunction with guided tissue regeneration on a tooth with complete loss of buccal bone due to cemental tear

Soohyeon Kim,Minju Song,Su-Jung Shin,Jeong-Won Park 대한치과보존학회 2010 Restorative Dentistry & Endodontics Vol.35 No.S2

영어능력 인증에 대한 비판적 담론분석

박수현(Soohyeon Park),신동일(Dongil Shin) 한국응용언어학회 2016 응용 언어학 Vol.32 No.4

This study aims at applying critical discourse analysis methodology to investigating Korean newspaper media reportage of Korean universities’ graduation accreditation system for English proficiency certification. In this study, the discourse event was discussed from three dimensions of textual, discursive, and social practice. It was found that a top-down communicative practice was mobilized to legitimize the need for English proficiency certification for college students in Korea. The voices of university presidents were frequently quoted in the aspect of style. By presenting their voices as authoritative (a portrayal enhanced by combining deferential presentation with the interview genre, in which an authoritative voice states definitive answers to questions posed), discourse producers regarded English language as an object to be managed, a problem to be solved, and a target to be mastered. It legitimized the dominant paradigm of language determinism, or monolingualism in internal and interdiscursive relations of the text.

중도입국자녀의 언어능력에 대한 비판적 담론분석

박수현(Park, SooHyeon),신동일(Shin, Dongil) 한국사회언어학회 2017 사회언어학 Vol.25 No.3

As one of the most important sites in which language policy is articulated and through which it is disseminated, printed media reportage plays important roles in agenda setting. Drawing on Fairclough s critical discourse analysis, this study examines the effects of intertextuality on the discursive construction of immigrated students and their language competency in selected Korean newspapers. It also aims to show how the newspapers employ specific discursive strategies to represent the immigrated students and their monolingual/bilingual competence from the neoliberal perspectives. Focusing on genre, style, and discourses, which are respectively associated with representational, identificational, and actional meaning of discourse, this study found that different discursive strategies were interwoven, and that they drew on deeply entrenched ideological beliefs about language and society, such as, language as language as problems, rights, capital, and resources It was concluded that the discourses in Korean media could be conceptualized in two intersecting continua informing social integration ideological debates.

기업교육과정에서 스토리텔링 진단평가도구의 활용에 관한 탐색 연구

신동일(Dongil Shin),김금선(Keumsun Kim),박수현(Soohyeon Park),김나희(Nahee Kim) 학습자중심교과교육학회 2019 학습자중심교과교육연구 Vol.19 No.6

본 연구의 목적은 국내외 다양한 분야의 학술문헌으로부터 수집된 스토리텔링 진단평가도구들의 차별적인 특성을 기업교육의 맥락과 실제적 채점 활동으로부터 이해하는 것이다. 이를 위해 연구팀은 특수교육, 유초등교육, 언어치료, 영어교육 등 다 양한 학술 분야로부터 관련 선행문헌을 검토했고, 삼성전자 직원 대상의 2017년 봄학기 스토리텔링 교육과정에 참여한 3명의 학습자들이 사전-중간-사후 평가도구 문항에 응답한 자료를 각기 다른 진단평가 모형에 적용해보았다. 스토리텔링 진단평가 의 대표적인 모형 8개(Bliss, McCabe, & Miranda, 1998, Gilllam & Person, 2008; Hedberg & Stoel-Gammon, 1986; Heilmann, Miller, & Nockerts, 2010; Justice etal., 2010; Labov & Waletzky, 1967; Stein & Glenn, 1979)로부터 연구팀은 학습자들의 구술 자료를 채점하고 개별적으로 작성한 채점자 일지를 공유하면서 각 평가도구의 특성을 탐색했다. 채점자들의 관점과 채점 결과는 2018년 1-2월 총 5회에 걸친 전체 회의로부터 공개적으로 논의되고 조정되었다. 본 연구는 채점자들이 공유한 진단평가 과업의 적절성, 평가등급과 채점절차의 명시성, 평가영역의 채점 수행성에 관한 논점을 요약했고 추후 기업교육, 스토리텔링 교육, 구술 진단평가에서 고려되어야 할 사안을 제시해 두었다. The purpose of this study is to examine diagnostic assessment of storytelling proficiency in business education. Over the decades, oral narrative skills have been deemed as a key component of language learning process, and the related diagnostic information has been significant interest to researchers and practitioners in speech pathology, children language learning, or first/second language acquisition. Few studies, however, have been devoted to storytelling assessment in EFL (English as Foreign Language) business education. In this study, eight diagnostic assessment models of storytelling were collected, revised, and evaluated by five experienced researchers and teachers in a business education program, where students enrolled on the course titled ‘English Storytelling Practice’ within Samsung Electronics. Oral narrative samples were analyzed by micro, macro, mixed narrative scoring schemes. It was found that as micro narrative scoring scheme had low practicality to raters, especially for time-consuming and ambiguous rubric, so did mixed narrative scoring scheme. Macro scoring scheme had relatively high practicality to raters, but it provided insufficient diagnostic information to upper intermediate level storytellers. Theses finding have implication for future development of diagnostic assessment instruments in localized and business contexts.

담론으로 접근하는 언어정책탐구 연구방법

신동일(Dongil Shin),박수현(Soohyeon Park) 한국응용언어학회 2019 응용 언어학 Vol.35 No.1

This paper is intended to show that LPP (language planning and policy) is a multilayered phenomenon constituted and practiced in and through discourse. It gives a brief history of four different approaches to LPP research. In the late 1950s and early 1960s, the exercise of language planning led to or was directed by the promulgation of a language policy by the government or other authoritative bodies. However, LPP is itself an instance of social change. It deems activities that move upwards as well as downwards. The field of LPP has been subject to a series of critical and discursive turns for the last decades. In the early 1990s, the CLP (critical language policy) emerged as a response to earlier language planning work. However, it has been criticized for being too deterministic and underestimating the power of human agency. Drawing on CDS (critical discourse studies), this study explicates how LPP has been interconnected with discourse beyond the text. Drawing from interdisciplinary literature related to LPP, it is argued that the contemporary DILP (discursive inquires to language policy) combines the macro and micro, offers a balance between policy power and interpretative agency from ethnographic research methods. Moreover, it can be committed to multicultural and multilingual issues in Korea, especially those that pertain the rights of indigenous and minority language speakers.

Superconductivity at 7.4 K in few layer graphene by Li-intercalation

Tiwari, Anand P,Shin, Soohyeon,Hwang, Eunhee,Jung, Soon-Gil,Park, Tuson,Lee, Hyoyoung IOP 2017 Journal of Physics, Condensed Matter Vol.29 No.44

<P>Superconductivity in graphene has been highly sought after for its promise in various device applications and for general scientific interest. Ironically, the simple electronic structure of graphene, which is responsible for novel quantum phenomena, hinders the emergence of superconductivity. Theory predicts that doping the surface of the graphene effectively alters the electronic structure, thus promoting propensity towards Cooper pair instability (Profeta <I>et al</I> (2012) <I>Nat. Phys</I>. <B>8</B> 131–4; Nandkishore <I>et al</I> (2012) <I>Nat. Phys</I>. <B>8</B> 158–63) [1, 2]. Here we report the emergence of superconductivity at 7.4 K in Li-intercalated few-layer-graphene (FLG). The absence of superconductivity in 3D Li-doped graphite underlines that superconductivity in Li-FLG arises from the novel electronic properties of the 2D graphene layer. These results are expected to guide future research on graphene-based superconductivity, both in theory and experiments. In addition, easy control of the Li-doping process holds promise for various device applications.</P>