AFM模式

切换光谱压电响应力显微镜（SS-PFM）

Quantitative ferroelectric hysteresis loop measurement with highest sensitivity and accuracy

Next-Generation Ferroelectric Materials Research with SS-PFM Mode

切换光谱压电响应力显微镜（SS-PFM）mode enables highly accurate nanoscale characterization of the properties of ferroelectric materials,expanding upon standard Piezoresponse Force Microscopy (PFM) by greatly improving the sensitivity and accuracy of measurements。此模式：

大大减少了electrostatic artifacts that can influence signals measured by traditional PFM modes while achieving comparatively higher sensitivity.
Provides hyperspectral maps of ferroelectric key parameters, revealing information about the XY heterogeneity of a sample and its correlation with other properties with an otherwise unattainable level of detail.
可以量化铁电滞后环的关键参数，并比较跨仪器，实验室和探针的材料性能。

Used alone or in conjunction with other AFM operational modes, SS-PFM provides new insights into the material microstructure/polarization switching relationship.

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带有阳性电静态常数的样品（例如PZT）的PFM响应。如果域的极化与增加的电场平行，则样品会扩展。

Typical clockwise ferroelectric hysteresis loop of a sample with positive electrostrictive constant. Key parameters include coercive biases (V0), nucleation bias (Vc), saturation response (Rs), and remnant response (R0). Each has a positive and negative version (i.e. V0+).

Achieve Higher Sensitivity for Ultimate Low Signal Performance

The signal levels in PFM are generally small, with typical amplitudes <10 pm/V. This is at the limit of what an AFM can detect. To address this, one of two approaches are generally taken:

增加交流刺激电压，这会增加PFM信号或
Mechanically amplifying the small PFM signal using the contact resonance of the cantilever.

对于许多样本，任意增加交流刺激电压不是实际方法。如果超出强制性偏差，则样品域将翻转（轮询）；测得的振幅将不准确。对于强制性偏置通常较低的薄膜尤其如此。

在频率扫描期间测得的悬臂振幅（顶部）和相位（底部）。近接触共振，幅度明显大，比相位较低的噪声要高。

To characterize low response ferroelectrics without domain flipping, SS-PFM:

Improves the signal-to-noise ratio by applying the AC voltage near the contact resonant frequency of the cantilever and measuring the response.
Provides accurate measurements of both amplitude (A) and quality factor (Q) of the resonance to enable quantification of the response (A/Q).
通过使用频率扫描和锁定放大器来测量响应，可以实现对A，Q和相位的更准确的测量，从而使更长的集成时间以获得最终的低信号性能。

执行准确的磁滞回路测量

Eliminate Artifacts

标准PFM允许通过纳米级分辨率测量铁电行为，但是测量的信号可能受悬臂上的静电力以及铁电反应的影响。这些可能会导致磁滞回路定量中的错误，甚至可以将非有产质材料误认为是铁电材料。必威手机客户端

SS-PFM模式提供：

Both off-field and on-field loops, separating read and write measurements with SS-PFM scripted spectroscopy.
Further mitigation of electrostatic artifacts by acquiring data at different read voltages as well as different write voltages.
Unambiguous phase and correct direction of hysteresis loop (and characterization sign of electrostrictive coefficient) withDCUBE-CR-PFM。

Top: The electrostatic force between the cantilever and the sample creates an artifact by influencing the PFM response. Bottom: Using a switching waveform, called the SS-PFM probing waveform, which contains multiple different read voltages, one can compensate for the electrostatic artifact.

地图铁电参数

By collecting and analyzing an array of SS-PFM spectra, it is possible to generate maps of the key piezoelectric parameters, demonstrating the variation in the ferroelectric properties across the XY plane with nanoscale resolution.

SS-PFM提供：

来自磁滞循环的关键铁电参数的高度敏感和可重复的点测量值。
Quantitative information—inaccessible via simpler imaging modes—through hyperspectral analysis of script data.

Maps of ferroelectric material properties, which can be correlated with properties drawn from other maps (piezoelectric map, chemical map, etc.).

顺时针，从顶部：PZT中的滞后循环显示关键参数；通过在10x10矩阵中的点收集光谱创建的VC+图；V0+的地图显示了先前轮询的区域。

避免接触模式以获得可重复的结果

标准PFM在接触模式下运行，这不适合在扫描过程中拖动在样品表面上拖动的AFM尖端损坏或位移的样品。较软的探针可能会部分缓解此问题，但更容易在PFM测量中进行静电伪像。

像布鲁克的唯一的DCUBE-PFM模式, SS-PFM avoids dragging the tip on the surface. This eliminates the harmful lateral forces that plague conventional contact mode based approaches. When combined with峰值敲击and MIROView for pre-scanning and navigation, contact mode can be avoided completely.

SS-PFM模式支持：

低冲击扫描聚合物，纤维和纳米颗粒等细腻样品。
Enhanced tip lifetime when working with hard samples.
More consistent PFM images without compromising signal measurement accuracy.

顺时针从左开始：带有SS-PFM Rampscript阵列的Miroview Canvas在PFM图像上；聚合物薄片的DCUBE-PFM图像；使用接触模式后使用的提示。

实验设计和分析的易用性和灵活性

Innovation with Advanced Software and Analysis

Bruker的最先进，易于访问的软件和分析工具提供了灵活性研究人员的需求。

Our easy-to-use script generator can create the switching waveform script from seven key parameters. Advanced users can also create unique scripts in XML.
Open-source Python-based analysis code enables researchers to see exactly how analysis works and develop innovative approaches to analyzing SS-PFM data.
For researchers developing their own electronics, a Signal Access Module (SAM 6) allows hardware access to raw signals and can also provide high voltage for samples with large coercive biases.