Coexistence of Haldane Gap Excitations and Long-Range Order in R{sub 2}BaNiO{sub 5} (R=Rare Earth)

Conference · Wed Dec 31 00:00:00 EST 1997

OSTI ID:620980

Zheludev, A

R2BaNiO5 (R = rare earth) quasi-1-D antiferromagnets are structurally equivalent to the well-studied 1-D S = 1 Haldane-gap compound Y2BaNiO5. Unlike the Y-nickelate though, these materials undergo 3-D magnetic ordering at finite temperatures. Recent inelastic neutron scattering studies of Pr2BaNiO5 and (Nd(x)Y(1-x))2BaNiO5 revealed purely one-dimensional gap excitations that propagate exclusively on the Ni-chains and are strikingly similar to Haldane gap modes in Y2BaNiO5. In the ordered phase these excitations survive and actually coexist with conventional spin waves. The results suggest that the Haldane singlet ground state of the Ni-chains is not fully destroyed by Neel ordering.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States); US-Japan Cooperative Neutron Scattering Program (United States); Ministry of Education, Science and Culture (Japan)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 620980
• Report Number(s): BNL-64557; CONF-970814-; ON: DE97008951; TRN: 98:006335
• Resource Relation: Conference: International conference on neutron scattering (ICNS), Toronto (Canada), 17-21 Aug 1997; Other Information: PBD: 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
GROUND STATES
RARE EARTH COMPOUNDS
INELASTIC SCATTERING
ANTIFERROMAGNETISM
NICKELATES
ENERGY GAP
EXCITATION
ORDER PARAMETERS