Behavior of acoustic axes and internal conical refraction in LiNbO (3) and SrTiO(3) crystals placed in an external electric field.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control · 1998 · Unclear · Insufficient evidence

← Research stream

UnclearInsufficient evidencePaper 4043

Study snapshot

PublicationIEEE transactions on ultrasonics, ferroelectrics, and frequency control · 1998

Study typeengineering

Reported directionUnclear

Evidence ratingInsufficient

Abstract

The behavior of acoustic axes and conical refraction are analyzed for lithium niobate and strontium titanate crystals, which are either mechanically squeezed or mechanically free and placed in an external electric field. Relying on numerical calculation, field dependencies of the acoustic axis shift and splitting angles have been elaborated, which are compared with the results obtained previously in the context of the theory of perturbations. External electric fields with the intensity E<10(7) V/m have yielded small (<1 degrees ) angles of acoustic axis splitting and shift; however, for greater field intensities, E>/=10(7) V/m, the rearrangement of the crystal's acoustic axes with respect to its initial position (E=O) assumes a "macroscopic nature". In particular, degeneracies having Poincare indexes with opposite signs may merge and "annihilate". We also first examined the variation of the conical refraction parameters versus the external electric field with transverse elastic waves which propagate along the acoustic axes of conical degeneracy in the above-mentioned materials. With actually achievable field strengths, the direction of energy velocity can be altered by several degrees. It is sufficient for the development of highly effective modulators, switchers, and acoustic wave gates to be used in various logic elements and other signal processing units.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionunclear

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

Numerical calculations for LiNbO3 and SrTiO3 crystals in an external electric field found small (<1°) acoustic axis splitting and shift for E < 10^7 V/m, while for E ≥ 10^7 V/m the rearrangement of acoustic axes becomes macroscopic and degeneracies with opposite-sign Poincaré indexes may merge and annihilate. Conical refraction parameters varied with the external electric field, and at achievable field strengths the direction of energy velocity could be altered by several degrees, suggesting applicability to modulators/switchers/acoustic wave gates.

Outcomes measured

acoustic axis shift
acoustic axis splitting angles
rearrangement/degeneracy behavior (Poincaré index merging/annihilation)
conical refraction parameters
direction of energy velocity (degrees of alteration)

Limitations

Numerical calculation study; no experimental validation described in the abstract
No biological/health outcomes assessed
Field characteristics beyond intensity (e.g., frequency/time variation) not specified

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": null,
    "source": "external electric field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "acoustic axis shift",
    "acoustic axis splitting angles",
    "rearrangement/degeneracy behavior (Poincaré index merging/annihilation)",
    "conical refraction parameters",
    "direction of energy velocity (degrees of alteration)"
  ],
  "main_findings": "Numerical calculations for LiNbO3 and SrTiO3 crystals in an external electric field found small (<1°) acoustic axis splitting and shift for E < 10^7 V/m, while for E ≥ 10^7 V/m the rearrangement of acoustic axes becomes macroscopic and degeneracies with opposite-sign Poincaré indexes may merge and annihilate. Conical refraction parameters varied with the external electric field, and at achievable field strengths the direction of energy velocity could be altered by several degrees, suggesting applicability to modulators/switchers/acoustic wave gates.",
  "effect_direction": "unclear",
  "limitations": [
    "Numerical calculation study; no experimental validation described in the abstract",
    "No biological/health outcomes assessed",
    "Field characteristics beyond intensity (e.g., frequency/time variation) not specified"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "lithium niobate",
    "LiNbO3",
    "strontium titanate",
    "SrTiO3",
    "external electric field",
    "acoustic axes",
    "conical refraction",
    "degeneracy",
    "Poincaré index",
    "energy velocity",
    "modulators",
    "switchers"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1109/58.660147
PubMed: 18244188

Read the original paper →

Related papers

← Back to the Research Library