Probing <math><mrow><msub><mi>Ca</mi><mn>3</mn></msub><msub><mi>Ti</mi><mn>2</mn></msub><msub><mi>O</mi><mn>7</mn></msub></mrow></math> crystal structure at the atomic level: Insights from perturbed angular correlation spectroscopy and ab initio studies

• Type: Article in International Scientific Journal
• Date: 2024

Authors

Rocha-Rodrigues, P (Author) Other; Miranda, IP (Author) Other; Santos, SSM (Author) Other; Oliveira, GNP (Author) FCUP; Leal, T (Author) Other; Marcondes, ML (Author) Other; Correia, JG (Author) Other; Assali, LVC (Author) Other; Petrilli, HM (Author) Other; Lopes, AML (Author) Other; Araújo, JP (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: PHYSICAL REVIEW B

Vol. 109

ISSN: 2469-9950

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Other information

Authenticus ID: P-012-R12

DOI: 10.1103/physrevb.109.224101

Abstract (EN): Perturbed angular correlation spectroscopy combined with ab initio electronic structure calculations is used to unravel the structural phase transition path from the low -temperature polar structure to the high -temperature structural phase in Ca 3 Ti 2 O 7 , a hybrid improper ferroelectric. The experimental procedure, conducted at ISOLDE, explores the unique features of a local probe environment approach by monitoring the evolution of the electric field gradient tensor at the calcium sites. The local environments, observed above 1057 K, confirm a structural phase transition from the A 2 1 am symmetry to an orthorhombic Acaa symmetry in the Ca 3 Ti 2 O 7 crystal lattice, disagreeing with the frequently reported avalanche structural transition from the polar A 2 1 am phase to the aristotype I 4 / mmm phase. Moreover, the EFG temperature dependency, within the A 2 1 am temperature stability, is shown to be sensitive to the recently proposed Ca 3 Ti 2 O 7 ferroelectric polarization decrease within the 500-800 K temperature range.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12