Lead-Free Piezoelectric Material Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piezoelectric materials used in devices often have low piezoelectric constants at high temperatures and low mechanical quality factors at low temperatures, making them unsuitable for a wide range of applications within the -30°C to 50°C device driving temperature range.
Innovation Solution
A lead-free piezoelectric material with a perovskite-type metal oxide composition represented by (Ba1-xCax)(Ti1-yZry)O3, incorporating Mn, Bi, and Li as auxiliary components, optimized to maintain high piezoelectric constants and mechanical quality factors across the specified temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional piezoelectric materials are used, then the piezoelectric constant is improved at room temperature, but the piezoelectric constant becomes low in the high temperature region of the device driving temperature range
Solution Approach 1:
The patent applies parameter changes by precisely controlling the compositional parameters x, y, z, and a in the perovskite structure (Ba1-xCax)a(Ti1-y-zZrySnz)O3. By optimizing these parameters within specific ranges, the material maintains high piezoelectric constant across the temperature range from -30°C to 50°C, resolving the contradiction between room temperature performance and high temperature performance.
Solution Approach 2:
The patent uses composite materials by combining multiple elements (Ba, Ca, Ti, Zr, Sn) in a perovskite structure with specific compositional ratios. This composite approach allows the material to exhibit both high piezoelectric constant at room temperature and maintained performance at elevated temperatures, satisfying the requirement for consistent performance across the device driving temperature range.
2Reliability
If conventional piezoelectric materials are used, then the mechanical quality factor is improved at room temperature, but the mechanical quality factor becomes low in the low temperature region of the device driving temperature range
Solution Approach 1:
The patent applies parameter changes by optimizing the compositional parameters x, y, z, and a within specific ranges to achieve a material that maintains high mechanical quality factor across the temperature range from -30°C to 50°C. This compositional optimization ensures that the material's mechanical properties remain stable in low temperature regions while maintaining overall reliability.
Solution Approach 2:
The patent applies local quality by creating a perovskite structure with non-uniform distribution of dopant elements (Ca at A site, Zr and Sn at B site) to achieve different local properties that collectively provide both high mechanical quality factor at room temperature and maintained performance at low temperatures.
3Object-affected harmful factors
If lead-free perovskite-type metal oxide is used, then environmental compatibility is improved, but the piezoelectric characteristics and mechanical quality factor are insufficient across the device driving temperature range
Solution Approach 1:
The patent uses composite materials by combining Ba, Ca, Ti, Zr, and Sn elements in a perovskite structure with optimized compositional ratios. This lead-free composite material achieves both environmental compatibility and satisfactory piezoelectric characteristics with mechanical quality factor across the device driving temperature range of -30°C to 50°C.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the compositional parameters x, y, z, and a in the lead-free perovskite structure. By optimizing these parameters within specific ranges, the material achieves both environmental compatibility (being lead-free) and satisfactory piezoelectric characteristics and mechanical quality factor across the required temperature range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The material provides a satisfactory piezoelectric constant and mechanical quality factor within the device driving temperature range, enhancing the performance and reliability of devices such as liquid discharge heads, ultrasonic motors, and image pickup devices.
Implementation Method 1
Piezoelectric materials are generally ABO3 perovskite-type metal oxides
Data Source
AI summary
Provided is a lead-free piezoelectric material having satisfactory piezoelectric constant and mechanical quality factor in a device driving temperature range (-30°C to 50°C). The piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula 1, a first auxiliary component composed of Mn, and a second auxiliary component composed of Bi or Bi and Li. The content of Mn is 0.040 parts by weight or more and 0.500 parts by weight or less based on 100 parts by weight of the metal oxide on a metal basis. The content of Bi is 0.042 parts by weight or more and 0.850 parts by weight or less and the content of Li is 0.028 parts by weight or less (including 0 parts by weight) based on 100 parts by weight of the metal oxide on a metal basis. (Ba1-xCax)a(Ti1-yZry)O3 ... (1), wherein, 0.030 ≤ x < 0.090, 0.030 ≤ y ≤ 0.080, and 0.9860 ≤ a ≤ 1.0200.