title: External stimulation-controllable heat-storage ceramics.
abstract: Commonly available heat-storage materials cannot usually store the energy for a prolonged period. If a solid material could conserve the accumulated thermal energy, then its heat-storage application potential is considerably widened. Here we report a phase transition material that can conserve the latent heat energy in a wide temperature range, T<530 K and release the heat energy on the application of pressure. This material is stripe-type lambda-trititanium pentoxide, λ-Ti3O5, which exhibits a solid-solid phase transition to beta-trititanium pentoxide, β-Ti3O5. The pressure for conversion is extremely small, only 600 bar (60 MPa) at ambient temperature, and the accumulated heat energy is surprisingly large (230 kJ L(-1)). Conversely, the pressure-produced beta-trititanium pentoxide transforms to lambda-trititanium pentoxide by heat, light or electric current. That is, the present system exhibits pressure-and-heat, pressure-and-light and pressure-and-current reversible phase transitions. The material may be useful for heat storage, as well as in sensor and switching memory device applications.
authors.affiliation: 1] Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] CREST, JST, K's Gobancho, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan [3] Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tokoro
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Marie
authors.initials: M
authors.lastname: Yoshikiyo
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Imoto
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Asuka
authors.initials: A
authors.lastname: Namai
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Nasu
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ozaki
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Hakoe
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Science and Technology System Div., Ryoka Systems Inc., Tokyo Skytree East Tower, 1-1-2 Oshiage, Sumida-ku, Tokyo 131-0045, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Chiba
authors.affiliation: 1] Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Osaka 599-8570, Japan [2] PRESTO, JST, 4-8-1 Honcho, Kawaguchi 332-0012, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Makiura
authors.affiliation: WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
authors.forename: Kosmas
authors.initials: K
authors.lastname: Prassides
authors.affiliation: 1] Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] CREST, JST, K's Gobancho, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ohkoshi