日本語フィールド
著者：鄭 旭光題名：Magnetism-induced ferroelectricity in cupric oxide CuO発表情報：China-Japan Symposium on Ferroelectric Materials and Their Applications, Aug 20-23, 2009, Dunhuang, Chinaキーワード：Magnetism-induced ferroelectricity in cupric oxide CuO概要：抄録：Recently we discovered a giant negative thermal expansion (NTE) in nanocrystals of CuO (1). This unique NTE effect is apparently correlated to the strong charge-spin-lattice coupling that we previously discovered for single crystals of CuO (2). This strong charge/spin coupling in bulk CuO is specifically classified as “multiferroic” and the “ferroelectric” CuO first reported by us is now viewed as intrinsic ferroelectric which receives intense attention (3). Here I will review the unique charge-spin-lattice coupling in bulk CuO, its dielectric properties, and the unusual lattice expansion in its nanocrystals. We hope that a re-inspection of its bulk dielectric properties and presentation of its detailed dielectric data to this conference would help us to reveal the mechanism for the unusual NTE in nanocrystal CuO.
The cupric oxide, CuO, is a unique transition metal mono oxide that crystallizes in monoclinic lattice and shows successive magnetic transitions (Fig. 1). The single crystals of CuO were clarified by us to show strong charge-spin-lattice coupling and ferroelectric properties below its antiferromagnetic transition (2). Our previous structure study also suggested dielectric and lattice anomalies at its magnetic transition temperatures (Néel temperature TN).
Our previous publication concentrated on slightly conductive samples of single crystals of CuO. Here we introduce the dielectric data for highly insulating CuO. The dielectric constants of single crystal CuO are shown in Fig. 2, which suggest transition into ferroelectric at the first magnetic transition TN1 = 229 K and slow evolution until TN2 = 213 K. These data clearly show the charge-spin coupling. More detailed data will be presented at the conference.英語フィールド
Author：X.G. ZhengTitle：Magnetism-induced ferroelectricity in cupric oxide CuOAnnouncement information:China-Japan Symposium on Ferroelectric Materials and Their Applications, Aug 20-23, 2009, Dunhuang, ChinaKeyword：Magnetism-induced ferroelectricity in cupric oxide CuOAn abstract：Recently we discovered a giant negative thermal expansion (NTE) in nanocrystals of CuO (1). This unique NTE effect is apparently correlated to the strong charge-spin-lattice coupling that we previously discovered for single crystals of CuO (2). This strong charge/spin coupling in bulk CuO is specifically classified as “multiferroic” and the “ferroelectric” CuO first reported by us is now viewed as intrinsic ferroelectric which receives intense attention (3). Here I will review the unique charge-spin-lattice coupling in bulk CuO, its dielectric properties, and the unusual lattice expansion in its nanocrystals. We hope that a re-inspection of its bulk dielectric properties and presentation of its detailed dielectric data to this conference would help us to reveal the mechanism for the unusual NTE in nanocrystal CuO.
The cupric oxide, CuO, is a unique transition metal mono oxide that crystallizes in monoclinic lattice and shows successive magnetic transitions (Fig. 1). The single crystals of CuO were clarified by us to show strong charge-spin-lattice coupling and ferroelectric properties below its antiferromagnetic transition (2). Our previous structure study also suggested dielectric and lattice anomalies at its magnetic transition temperatures (Néel temperature TN).
Our previous publication concentrated on slightly conductive samples of single crystals of CuO. Here we introduce the dielectric data for highly insulating CuO. The dielectric constants of single crystal CuO are shown in Fig. 2, which suggest transition into ferroelectric at the first magnetic transition TN1 = 229 K and slow evolution until TN2 = 213 K. These data clearly show the charge-spin coupling. More detailed data will be presented at the conference.